The Project Gutenberg EBook of A Synopsis of the North American Lagomorpha, by E. Raymond Hall This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at www.gutenberg.org Title: A Synopsis of the North American Lagomorpha Author: E. Raymond Hall Release Date: May 19, 2010 [EBook #32426] Language: English Character set encoding: ISO-8859-1 *** START OF THIS PROJECT GUTENBERG EBOOK NORTH AMERICAN LAGOMORPHA *** Produced by Chris Curnow, Simon Gardner, Joseph Cooper and the Online Distributed Proofreading Team at http://www.pgdp.net Transcriber's Note The scale in several figure captions ("All × 1") is taken from the original text; actual sizes may be larger or smaller, depending on your monitor and browser settings. The dimensions correspond to a monitor resolution of 96 pixels per inch and browser magnification of 100%. Minor changes to the text have been listed at the end of this book. Table of Contents Introduction Order LAGOMORPHA—Hares, Rabbits and Pikas Family Ochotonidae—Pikas Genus Ochotona Link—Pikas Subgenus PIKA Lacépède Family Leporidae—Rabbits and Hares Genus Romerolagus Merriam—Volcano Rabbit Genus Sylvilagus Gray—Cottontails and Allies Subgenus BRACHYLAGUS Miller—Pigmy Rabbit Subgenus SYLVILAGUS Gray—Cottontails and Allies Genus Lepus Linnaeus—Hares and Jack Rabbits LITERATURE CITED A Synopsis of the North American Lagomorpha BY E. RAYMOND HALL University of Kansas Publications Museum of Natural History Volume 5, No. 10, pp. 119-202, 68 figures in text December 15, 1951 University of Kansas LAWRENCE 1951 UNIVERSITY OF KANSAS PUBLICATIONS The University of Kansas Publications, Museum of Natural History, are offered in exchange for the publications of learned societies and institutions, universities and libraries. For exchanges and information, address the Exchange Desk, University of Kansas Library, Lawrence, Kansas, U. S. A. Museum of Natural History.—E. Raymond Hall, Chairman, Editorial Committee. This series contains contributions from the Museum of Natural History. Cited as Univ. Kans. Publ., Mus. Nat. Hist. Vol. 1. (Complete) Nos. 1-26. Pp. 1-638. August 15, 1946-January 20, 1951. Vol. 2. (Complete) Mammals of Washington. By Walter W. Dalquest. Pp. 1-444, 140 figures in text. April 9, 1948. Vol. 3. 1. The avifauna of Micronesia its origin, evolution, and distribution. By Rollin H. Baker. Pp. 1-359, 16 figures in text. June 12, 1951. 2. A quantitative study of the nocturnal migration of birds. Pp. 361-472, 47 figures in text. June 29, 1951. 3. Phylogeny of the waxwings and allied birds. By M. Dale Arvey. Pp. 473-530, 49 figures in text, 13 tables. October 10, 1951. 4. Birds from the state of Veracruz, Mexico. By George H. Lowery, Jr., and Walter W. Dalquest. Pp. 531-649, 7 figures in text, 2 tables. October 10, 1951. Vol. 4. In press. Vol. 5. 1. Preliminary survey of a Paleocene faunule from the Angels Peak Area, New Mexico. By Robert W. Wilson. Pp. 1-11, 1 figure in text. February 24, 1951. 2. Two new moles (genus Scalopus) from Mexico and Texas. By Rollin H. Baker. Pp. 17-24. February 28, 1951. 3. Two new pocket gophers from Wyoming and Colorado. By E. Raymond Hall and H. Gordon Montague. Pp. 25-32. February 28, 1951. 4. Mammals obtained by Dr. Curt von Wedel from the barrier beach of Tamaulipas, Mexico. By E. Raymond Hall. Pp. 33-47, 1 figure in text. October 1, 1951. 5. Comments on the taxonomy and geographic distribution of some North American rabbits. By E. Raymond Hall and Keith R. Kelson. Pp. 49-58. October 1, 1951. 6. Two new subspecies of Thomomys bottae from New Mexico and Colorado. By Keith R. Kelson. Pp. 59-71, one figure in text. October 1, 1951. 7. A new subspecies of Microtus montanus from Montana and comments on Microtus canicaudus Miller. By E. Raymond Hall and Keith R. Kelson. Pp. 73-79. October 1, 1951. 8. A new pocket gopher (genus Thomomys) from Eastern Colorado. By E. Raymond Hall. Pp. 81-85. October 1, 1951. 9. Mammals taken along the Alaska highway. By Rollin H. Baker. Pp. 87-117, 1 figure in text. November 28, 1951. 10. A synopsis of the North American Lagomorpha. By E. Raymond Hall. Pp. 110-202, 68 figures in text. December 15, 1951. A Synopsis of the North American Lagomorpha BY E. RAYMOND HALL University of Kansas Publications Museum of Natural History Volume 5, No. 10, pp. 119-202, 68 figures in text December 15, 1951 University of Kansas LAWRENCE 1951 University of Kansas Publications, Museum of Natural History Editors: E. Raymond Hall, Chairman, A. Byron Leonard, Edward H. Taylor, Robert W. Wilson Volume 5, No. 10, pp. 119-202, 68 figures in text December 15, 1951 University of Kansas Lawrence, Kansas PRINTED BY FERD VOILAND, JR., STATE PRINTER TOPEKA, KANSAS 1951 23-7988 A Synopsis of the North American Lagomorpha BY E. RAYMOND HALL The most popular small game mammal in nearly every part of North America is one or another of the species of rabbits or hares. The rabbit is one of the few species of wild game that still is hunted commercially and sold for food on the open market. The close association and repeated contact of man with these animals has resulted in his contracting such of their diseases as are transmissible to him. Consequently the rabbits and hares have figured in many investigations concerned with public health and medicine. Because the number of such investigations is increasing, there has been an increasing number of specimens of these animals submitted to mammalogists for identification; also, inquiries are received as to the degree of relationship between two or more of the named kinds of rabbits in which identical, or closely related, disease organisms have been found; other inquiries have to do with the degree of relationship of named kinds of rabbits and hares in widely separated parts of the continent. The monographs to which the investigator could turn to obtain answers to some of these questions are Arthur H. Howell's "Revision of the American Pikas" (1924), and Edward H. Nelson's "The Rabbits of North America" (1909) published 27 and 42 years ago, respectively. These monographs are still excellent sources of detailed information, as, of course, also is Marcus Ward Lyon's "Classification of the Hares and their Allies" (1904). The acquisition of additional study specimens in recent years, however, has provided new data on the geographic occurrence of several species, and study of these specimens has given basis for a different arrangement of several named kinds of the lagomorphs. Two principal aims of the present synopsis, therefore, are to combine in one publication the current taxonomic arrangement and as much as is known of the geographic distribution of the several species and subspecies. The maps herewith and listings of marginal localities are the means chosen to present the information on geographic distribution. The artificial key is supplemented by line drawings of skulls of certain species and by a minimum of text to aid the user of the key. The skulls are necessary for the identification of some species of the genus Sylvilagus. The skins, on the contrary, are essential for the identification of the species of the genus Lepus in central Mexico and in the Great Basin of the western United States. Consequently, it has been impossible to construct a key based on external characters only or on cranial features only. Furthermore, the only apparent differences between a given pair of species in one region may not be apparent in another region where the same two species occur together. A case in point is provided by Sylvilagus floridanus and Sylvilagus nuttallii where the Great Plains meet the eastern flank of the Rocky Mountains and where the Sonoran desert meets the southwestern flank of these mountains. The details are described by Hall and Kelson (1951:52, 53) and are indicated in the part of the accompanying artificial key that takes out the species Sylvilagus nuttallii. Because of this geographic change in specific characters and because of the slight amount of difference between certain species of leporids, I have frequently resorted to geography, instead of to morphology alone, in constructing the artificial key. Despite this fault of the key to the lagomorphs, it, and the accompanying account, I hope, will aid workers who need to identify kinds of lagomorphs and to know about their geographic distribution. Another reason for presenting a synopsis of the lagomorphs at this time is that the presentation may bring suggestions for improvement in the arrangement of the kind of information presented here; an account along similar lines for all of the [Pg 121] [Pg 122] kinds of mammals native to North America is in prospect. Corrections of, and additions to, the material presented here will be welcomed and I shall be especially grateful for suggestions as to a more useful arrangement of the data. In arranging the families, genera and species the aim has been, in each category, to list the most primitive members first and to list last the one which presents the highest total of specialization. The term total of specialization is used here, as Miller (1924:2) used it, to denote the sum of the physical modifications which any mammal, or taxonomic category of mammals, is supposed by the author to have undergone during the course of its development away from its original or generalized mammalian stock. Subspecies of any one species are arranged alphabetically. On the maps, of course, the subspecies are shown in their correct geographic positions. For each subspecies, or species if it has not been divided into subspecies, there is given (1) the accepted scientific name (selected in accordance with the rules of the International Commission of Zoological Nomenclature); (2) a citation to the account in which the terminal part of the name was first proposed (the original description of zoological parlance) followed by a statement of the type locality; (3) a citation to the account in which the combination of names (generic, specific and subspecific) used in the present account first was employed unless the name combination used here is the same as that in the original description; (4) synonyms arranged in chronological order, and (5) marginal record stations of occurrence. These marginal records are arranged in clockwise order beginning with the northernmost locality. If more than one of the marginal localities lies on the line of latitude that is northernmost for a given kind of mammal, the westernmost of these is recorded first. The marginal localities that are represented by symbols on the corresponding distribution map are in Roman type. Italic type is used for those marginal localities that could not be represented by symbols on the map because undue crowding, or overlapping, of the symbols would have occurred. An understanding of how these localities are arranged and knowledge as to which of these localities are shown on the map will permit a person to associate any symbol on a map with its corresponding place name. Measurements are in millimeters unless otherwise indicated. Capitalized color terms are after Ridgway (Color Standards and Color Nomenclature, Washington, D. C., 1912), and uncapitalized terms refer to no particular color standard. Several of the drawings of skulls were reproduced originally in the "Mammals of Nevada" (Hall, 1946) and I am grateful to the University of California Press for permission to use them here. Those drawings were made by Miss Viola Memmler. The other drawings are the work of Mrs. Frieda Abernathy, Mrs. Diane (Danley) Sandidge, and Mrs. Virginia (Cassel) Unruh. Initials on the drawings identify the individual's work. The study here reported upon was aided by a contract between the Office of Naval Research, Department of the Navy, and the University of Kansas (NR 161- 791). Also, assistance with some of the field work was given by the Kansas University Endowment Association and by Dr. Curt von Wedel. For the corrected dates on several publications I am indebted to Dr. A. Remington Kellogg. For assistance with the organization of the data for the present account I am grateful to several persons, especially to my wife, Mary F. Hall, and to Dr. Keith R. Kelson. Order LAGOMORPHA—Hares, Rabbits and Pikas Families and genera revised by Lyon, Smithsonian Miscl. Coll., 45:321-447, June 15, 1904. For taxonomic status of group see Gidley, Science, n. s., 36:285-286, August 30, 1912. The order Lagomorpha is old in the geological sense; fossilized bones and teeth of both pikas and rabbits are known from deposits of Oligocene age and even at that early time the structural features distinguishing these animals from other orders were well developed. A noteworthy character of the order is the presence of four upper incisor teeth (instead of only two as in the Rodentia); also, the fibula is ankylosed to the tibia and articulates with the calcaneum. Each of the first upper incisors has a longitudinal groove on its anterior face. All lagomorphs are herbivorous. They eat principally leaves and non-woody stems although the bark of sprouts and bushes is taken as second choice by rabbits and hares. Correlation of structure and function is well illustrated among the lagomorphs by the means which the different species employ to detect and escape from their enemies. A gradient series is evident in which the pikas and jack rabbits are the extremes. The black-tailed jack rabbit, for example, in relation to size of the entire animal, has the longest ears and longest hind legs. This kind of lagomorph takes alarm when an enemy, for example, a coyote, is yet a long way off. The jack rabbit seeks safety in running; even when being overtaken by a pursuer that is close behind, the jack rabbit still relies on its running ability instead of entering thick brush or a hole in the ground where its larger-sized pursuer would be unable to follow. A cottontail has shorter ears and shorter hind legs. It allows the enemy to approach more closely than the jack rabbit does before running, and then, although relying in some measure on its running ability for escape, flees to a burrow or thicket for safety from its pursuer. The brush rabbit with ears and hind legs shorter than those of the cottontail seldom if ever ventures farther than 45 feet away from the edge of dense cover. After an enemy is near, the [Pg 123] [Pg 124] brush rabbit has merely to scamper back into the brush. Still shorter of ear and hind leg is the pigmy rabbit which ventures outside its burrow to feed only among the tall and closely-spaced bushes of sagebrush among which its burrow is dug. Detection of the slightest movement of an enemy on the opposite side of the bush sends the pigmy rabbit, in one or a few jumps, into the mouth of its burrow and, if need be, below ground. The pika, with the shortest ears and legs of all, lives in the rock slides and has to do little more than drop off the top of a rock into a space between the broken rocks when an enemy is detected near enough to the pika to have a chance of seizing it. The number of molts in a year, depending on the kind of lagomorph, varies in adults from one (according to Nelson, 1909:31) in the cottontails (genus Sylvilagus) to as many as three (according to Lyman, 1943, and Severaid, 1945) in the varying hare (Lepus americanus). Difficulties that I have experienced in attempting to account for the variations in color and wear of the pelage of the pika, Ochotona princeps, on the basis of two molts per year, make me wonder if it, too, has three molts. Lepus townsendii certainly has at least two molts per year. Key to Families and Genera of Lagomorpha 1. Hind legs scarcely larger than forelegs; hind foot less than 40; nasals widest anteriorly; no supraorbital process on frontal; five cheek teeth on each side above Family Ochotonidae, Genus Ochotona, p. 125 1´. Hind legs notably larger than forelegs; hind foot more than 40; nasals widest posteriorly; supraorbital process on frontal; six cheek teeth on each side above Family Leporidae, p. 134 2. Interparietal fused with parietals (see fig. 49); hind foot usually more than 105 Genus Lepus, p. 170 2´. Interparietal not fused with parietals (see fig. 10); hind foot usually less than 105 Genera Romerolagus and Sylvilagus, pp. 137, 138 Family Ochotonidae—Pikas Certain characters in which this family differs from the Leporidae (hares and rabbits) are: hind legs scarcely longer than forelegs; ears short, approximately as wide as high; no postorbital process on frontal; rostrum slender; nasals widest anteriorly; maxilla not conspicuously fenestrated; jugal long and projecting far posteriorly to zygomatic arm of squamosal; no pubic symphysis; one less cheek-tooth above, the dental formula being i. 2/1, c. 0/0, p. 3/2, m. 2/3; second upper maxillary tooth unlike third in form; last lower molar simple (not double) or absent (in the extinct genus Oreolagus); cutting edge of first upper incisor V-shaped; mental foramen situated under last lower molar. Genus Ochotona Link—Pikas Revised by A. H. Howell, N. Amer. Fauna, 47:1-57, August 21, 1924. 1795. Ochotona Link, Beyträge zur Naturgesch, I (pt. 2):74. Type, Lepus ogotona Pallas. Characters.—Five teeth (excluding incisor) in lower jaw; first cheek-tooth (p3) with more than one re-entrant angle; columns of lower molars angular internally; transverse width of any one column of a lower molariform tooth more than double the width of the neck connecting it to the other column. Subgenus PIKA Lacépède 1799. Pika Lacépède, Tableau des Divisions &c., Mamm., p. 9. Type, Lepus alpinus Pallas. 1904. Pika, Lyon, Smiths. Misc. Coll., 45:438, June 15. Characters.—Skull flattened; interorbital region wide; maxillary orifice roundly triangular; palatal foramina separate from anterior palatine foramina. All of the living members of the family Ochotonidae belong to this genus. American pikas all belong to the subgenus Pika, which occurs also in Eurasia. The distribution is boreal and the animals live in talus. This broken rock at the foot of a cliff provides interstices in which the animals live and store grass and herbs. These plant materials are cut for food and stacked in piles to dry in the sun, often beneath slabs of rock which protect the hay-piles from rain. Pikas are diurnal, active throughout the year, and have a characteristic call, "chickck-chickck." Young number two to five per litter. [Pg 125] [Pg 126] Figs. 1-4. Ochotona princeps tutelata, Greenmonster Canyon, 8150 feet, No. 38519 MVZ, ♂, × 1. Key to Nominal Species of Ochotona 1. North of 58° N latitude; underparts creamy white, without buffy wash; an indistinct grayish "collar" on shoulders collaris, p. 126 1´. South of 58° N latitude; underparts washed with buff; no grayish "collar" on shoulders princeps, p. 127 Ochotona collaris (Nelson) Collared Pika 1893. Lagomys collaris Nelson, Proc. Biol. Soc. Washington, 8:117, December 21, type from near head of Tanana River, Alaska. 1897. [Ochotona] collaris, Trouessart, Catalogus Mammalium ..., p. 648 Marginal records.—Alaska: Mt. McKinley (A. H. Howell, 1924:36). Yukon: head of Coal Creek, Ogilvie Mountains (ibid.). Mackenzie: mile 63E on Little Keel River, Canol Road (Anderson, 1947:94). Yukon: Macmillan Pass, mile 282, Canol Road (ibid.); Ross River, mile 96, Canol Road (ibid.); vic. Teslin Lake (A. H. Howell, 1924:36). British Columbia: Tagish Lake (ibid.); Stonehouse Creek, 5-1/2 mi. W jct. Stonehouse Creek and Kelsall River (29088 KU). Alaska: Tanana River (A. H. Howell, 1924:36). Upper parts Drab to Light Drab; underparts creamy white; grayish patch on nape and shoulders; skull broad; tympanic bullae large; total length 189; hind foot, 30. Ochotona princeps Pika Total length, 162-216; hind foot, 25-35; weight of O. p. tulelata, 6 ♂ 121 (108-128), 2 ♀ 121 and 129 grams. Upper parts varying from grayish to Cinnamon-Buff depending on the subspecies; underparts with wash of buff. Eight Nevadan females had an average of 3.1 (2-4) embryos. The mode was 3. Ochotona princeps albata Grinnell. 1912. Ochotona albatus Grinnell, Univ. California Publ. Zool., 10:125, January 31, type from 11,000 ft., near Cottonwood Lakes, Sierra Nevada, Inyo County, California. Marginal records (A. H. Howell, 1924:45).—California: Bullfrog Lake; 10,000 ft., Independence Creek; type locality; Mineral King, E. Fork Kaweah River. Ochotona princeps brooksi A. H. Howell. 1924. Ochotona princeps brooksi A. H. Howell, N. Amer. Fauna, 47:30, August 21, type from Sicamous, British Columbia. Marginal records.—British Columbia: Mountains E Shuswap Lake (Anderson, 1947:95); type locality; McGillivary Creek, Lillooet Dist. (A. H. Howell, 1924:31). Ochotona princeps brunnescens A. H. Howell. 1919. Ochotona fenisex brunnescens A. H. Howell, Proc. Biol. Soc. Washington, 32:108, May 20, type from Keechelus, Kittitas County, Washington. 1924. Ochotona princeps brunnescens A. H. Howell, N. Amer. Fauna, 47:31, September 23. [Pg 127] Fig. 5. Distribution of Ochotona collaris and Ochotona princeps. Marginal records.—British Columbia: Alta Lake (Anderson, 1947:95); Hope, Lake House (A. H. Howell, 1924:33). Washington: Whatcom Pass (Dalquest, 1948:380); Stevens Pass (A. H. Howell, 1924:33); Cowlitz Pass (Dalquest, 1948:380). Oregon: Mt. Hood (A. H. Howell, 1924:33); Crater Lake (ibid.); Mt. McLoughlin (V. Bailey, 1936:116); Diamond Lake (A. H. Howell, 1924:33). Washington: Tumtum Mtn. (Dalquest, 1948:380); Mt. Index (A. H. Howell, 1924:33). British Columbia: Chilliwack (ibid.); Vancouver (ibid.). 1. O. collaris 2. O. p. princeps 3. O. p. lutescens 4. O. p. septentrionalis 5. O. p. brooksi 6. O. p. cuppes 7. O. p. brunnescens 8. O. p. fenisex 9. O. p. fumosa 10. O. p. jewetti 11. O. p. taylori 12. O. p. schisticeps 13. O. p. muiri 14. O. p. albatus 15. O. p. sheltoni 16. O. p. tutelata 17. O. p. nevadensis 18. O. p. uinta 19. O. p. moorei 20. O. p. cinnamomea 21. O. p. fuscipes 22. O. p. utahensis 23. O. p. howelli 24. O. p. lemhi 25. O. p. goldmani 26. O. p. clamosa 27. O. p. ventorum 28. O. p. levis 29. O. p. figginsi 30. O. p. saxatilis 31. O. p. nigrescens 32. O. p. incana Ochotona princeps cinnamomea J. A. Allen. 1905. Ochotona cinnamomea J. A. Allen, Mus. Brooklyn Inst. Arts and Sci., Sci. Bull., 1:121, March 31, type from 11,000 ft., Briggs [=Britts] Meadows, Beaver Range, Beaver County, Utah (5 mi. by road W Puffer Lake, according to Hardy, Jour. Mamm., 26:432, February 12, 1946). Known from type locality only. 1934. Ochotona princeps cinnamomea, Hall, Proc. Biol. Soc. Washington, 47:103, June 13. Ochotona princeps clamosa Hall and Bowlus. 1938. Ochotona princeps clamosa Hall and Bowlus, Univ. California Publ. Zool., 42:335, October 12, type from 8400 ft., north rim Copenhagen Basin, Bear Lake County, Idaho. Marginal records.—Idaho: type locality; Deep Lake, Bear River Mts. (Hall and Bowlus, 1938:336) 2 mi. E Strawberry Creek Ranger Station, Wasatch Mts. (Davis, 1939:352). Ochotona princeps cuppes Bangs. 1899. Ochotona cuppes Bangs, Proc. New England Zool. Club, 1:40, June 5, type from 4000 ft., Monashee Divide, Gold Range, British Columbia. 1924. Ochotona princeps cuppes, A. H. Howell, N. Amer. Fauna, 47:27, September 23. Marginal records.—British Columbia: Glacier (A. H. Howell, 1924:28); Nelson (Anderson, 1947:95). Idaho: Cabinet Mts. (Davis, 1939:348). Washington: Sullivan Lake (A. H. Howell, [Pg 128] [Pg 129] 1924:28). British Columbia: Rossland (ibid.); type locality. Ochotona princeps fenisex Osgood. 1913. Ochotona fenisex Osgood, Proc. Biol. Soc. Washington, 26:80, March 22 (substitute for minimus Lord, type from 7000 ft., Ptarmigan Hill, near head of Ashnola River, Cascade Range, British Columbia). 1924. Ochotona princeps fenisex, A. H. Howell, N. Amer. Fauna, 47:28, September 23. 1863. Lagomys minimus Lord, Proc. Zool. Soc. London, p. 98. (Not of Schinz, 1821.) 1899. Ochotona minimus, Bangs, Proc. New England Zool. Club, 1:39, June 5. Marginal records.—British Columbia: Okanagan (A. H. Howell, 1924:30). Washington: Horseshoe Basin, "near" Mt. Chopaka (ibid.); mts. near Wenatchee (ibid.); Steamboat Mtn. (Dalquest, 1948:380); Easton (ibid.); Lyman Lake (ibid.); Barron (A. H. Howell, 1924:30). British Columbia: Tulameen (ibid.); 2500 ft., mts. W Okanagan Lake (ibid.). Ochotona princeps figginsi J. A. Allen. 1912. Ochotona figginsi J. A. Allen, Bull. Amer. Mus. Nat. Hist., 31:103, May 28, type from Pagoda Peak, Rio Blanco County, Colorado. 1924. Ochotona princeps figginsi, A. H. Howell, N. Amer. Fauna, 47:21, September 23. Marginal records (A. H. Howell, 1924:22).—Wyoming: Bridger Peak, Sierra Madre. Colorado: Mt. Zirkel; Trappers Lake; Crested Butte; Irwin; type locality; Sand Mtn., 9 mi. SW Hahns Peak P. O. Ochotona princeps fumosa A. H. Howell. 1919. Ochotona fenisex fumosa A. H. Howell, Proc. Biol. Soc. Washington, 32:109, May 20, type from Permilia Lake, W base Mt. Jefferson, Linn County, Oregon. 1924. Ochotona princeps fumosa A. H. Howell, N. Amer. Fauna, 47:33, September 23. Marginal records (A. H. Howell, 1924:34).—Oregon: About 900 ft., 15 mi. above Estacada; Paulina Lake; Three Sisters; Lost Creek Ranger Station, 10 mi. SE McKenzie Bridge. Ochotona princeps fuscipes A. H. Howell. 1919. Ochotona schisticeps fuscipes A. H. Howell, Proc. Biol. Soc. Washington, 32:110, May 20, type from Brian Head, Parowan Mts., Iron County, Utah. 1941. O[chotona]. p[rinceps]. fuscipes, Hall and Hayward, The Great Basin Naturalist, 2:108, July 20. Marginal records.—Utah: type locality; 9000 ft., Duck Creek (Durrant, MS). Ochotona princeps goldmani A. H. Howell. 1924. Ochotona schisticeps goldmani A. H. Howell, N. Amer. Fauna, 47:40, September 23, type from Echo Crater, Snake River Desert, 20 mi. SW Arco, Idaho. 1938. Ochotona princeps goldmani, Hall and Bowlus, Univ. California Publ. Zool., 42:337, October 12. Marginal records.—Idaho: S base Grassy Cone (Davis, 1939:350); type locality; Fissure Crater (A. H. Howell, 1924:41); Great Owl Cavern (Davis, 1939:350). Ochotona princeps howelli Borell. 1931. Ochotona princeps howelli Borell, Jour. Mamm., 12:306, August 24, type from 7500 ft., near head of Bear Creek, summit of Smith Mtn., S end Seven Devils Mts., Adams County, Idaho. Marginal records.—Idaho: 1/2 mi. E Black Lake (Davis, 1939:350); type locality. Ochotona princeps incana A. H. Howell. 1919. Ochotona saxatilis incana A. H. Howell, Proc. Biol. Soc. Washington, 32:107, May 20, type from 12,000 ft., Pecos Baldy, Santa Fe County, New Mexico. 1924. Ochotona princeps incana A. H. Howell, N. Amer. Fauna, 47:25, September 23. Marginal records.—Colorado: Medano Creek (A. H. Howell, 1924:25). New Mexico: Wheeler [Pg 130] Peak (V. Bailey, 1932:64); type locality. Ochotona princeps jewetti A. H. Howell. 1919. Ochotona schisticeps jewetti A. H. Howell, Proc. Biol. Soc. Washington, 32:109, May 20, type from head of Pine Creek, near Cornucopia, S slope Wallowa Mts., Baker County, Oregon. Marginal records (A. H. Howell, 1924:42).—Oregon: Wallowa Lake; Cornucopia, near head East Pine Creek; Anthony; Strawberry Butte; Austin. Ochotona princeps lemhi A. H. Howell. 1919. Ochotona uinta lemhi A. H. Howell, Proc. Biol. Soc. Washington, 32:106, May 20, type from Lemhi Mountains, 10 mi. W Junction, Lemhi County, Idaho. 1924. Ochotona princeps lemhi A. H. Howell, N. Amer. Fauna, 47:16, September 23. Marginal records.—Idaho: Elk Summit, about 15 mi. SE Warren (A. H. Howell, 1924:18); mts. E of Leadore (ibid.); mts. E of Birch Creek (ibid.); Ketchum (ibid.); Stanley Lake (ibid.); 5 mi. W Cape Horn (Davis, 1939:348). Ochotona princeps levis Hollister. 1912. Ochotona levis Hollister, Proc. Biol. Soc. Washington, 25:57, April 13, type from Chief Mountain [= Waterton] Lake, Alberta. 1924. Ochotona princeps levis, A. H. Howell, N. Amer. Fauna, 47:16, September 23. Marginal records (A. H. Howell, 1924:16).—Alberta: type locality. Montana: Little Belt Mts.; Belt Mts.; Chief Mountain Lake. Ochotona princeps lutescens A. H. Howell. 1919. Ochotona princeps lutescens A. H. Howell, Proc. Biol. Soc. Washington, 32:105, May 20, type from approximately 8000 ft., Mount Inglismaldie, near Banff, Alberta. Marginal records.—Alberta: Mistaya Creek, Banff-Jasper Highway (Anderson, 1947:96); Canmore (A. H. Howell, 1924:15); Mt. Forget-me-not, 50 to 75 mi. SW Calgary (ibid.). Ochotona princeps moorei Gardner. 1950. Ochotona princeps moorei Gardner, Jour. Washington Acad. Sci., 40:344, October 23, 1950, type from 10,000 ft., 1 mi. NE Baldy Ranger Station, Manti Nat'l Forest, Sanpete County, Utah. Known from type locality only. Ochotona princeps muiri Grinnell and Storer. 1916. Ochotona schisticeps muiri Grinnell and Storer, Univ. California Publ. Zool., 17:6, August 23, type from 9300 ft., Ten Lakes, Yosemite Nat'l Park, California. 1934. Ochotona princeps muiri, Hall, Proc. Biol. Soc. Washington, 47:103, June 13. Marginal records.—Nevada (Hall, 1946:593): 8500 ft., 3 mi. S Mt. Rose, California (A. H. Howell, 1924:44): Markleeville; mts. W Bishop Creek; Washburn Lake; Latitude 39°, summit of Sierra. Ochotona princeps nevadensis A. H. Howell. 1919. Ochotona uinta nevadensis A. H. Howell, Proc. Biol. Soc. Washington, 32:107, May 20, type from 10,500 ft., Ruby Mts., SW Ruby Valley P. O., Elko County, Nevada. 1924. Ochotona princeps nevadensis A. H. Howell, N. Amer. Fauna, 47:21, September 23. Marginal records.—Nevada: 7830 ft., Long Creek (Hall, 1946:590); type locality. Ochotona princeps nigrescens V. Bailey. 1913. Ochotona nigrescens V. Bailey, Proc. Biol. Soc. Washington, 26:133, May 21, type from 10,000 ft., Jemez Mountains, Bernalillo County, New Mexico. 1924. Ochotona princeps nigrescens, A. H. Howell, N. Amer. Fauna, 47:26, September 23. Marginal records (A. H. Howell, 1924:26).—Colorado: Upper Navajo River; Osier. New Mexico: type locality. Colorado: Navajo Peaks. Ochotona princeps princeps (Richardson). [Pg 131] [Pg 132] 1828. Lepus (Lagomys) princeps Richardson, Zool. Jour., 3:520, type from headwaters of Athabaska River, near Athabaska Pass, Alberta. 1897. [Ochotona] princeps, Trouessart, Catalogus Mammalium, p. 648. Marginal records.—British Columbia: headwaters South Pine River (Anderson, 1947:95). Alberta: Muskeg Creek "about" 60 mi. N Jasper House (ibid.). British Columbia: Morrissey (ibid.). Montana: mts. near St. Marys Lake (A. H. Howell, 1924:14); mts. 15 mi. E Corvallis (ibid.); Lake Como, Bitterroot Mts. (ibid.). Idaho: Coeur d' Alene Nat'l Forest (Rust, 1946:322). British Columbia: Mt. Evans, "near" Cranbrook (A. H. Howell, 1924:14); Spillamacheen River (ibid.) Ochotona princeps saxatilis Bangs. 1899. Ochotona saxatilis Bangs, Proc. New England Zool. Club, 1:41, June 5, type from Montgomery, "near" Mt. Lincoln, Park County, Colorado. 1924. Ochotona princeps saxatilis, A. H. Howell, N. Amer. Fauna, 47:23, September 23. Marginal records (A. H. Howell, 1924:24, except as otherwise noted).—Wyoming: Medicine Bow Mts.; just above Centennial in mts. (Martin, 1943:394). Colorado: Estes Park; Pikes Peak; Silverton. Utah: La Sal Mts. Colorado: Crystal Lake, 5 mi. W Lake City; Middle Brush Creek; Ten Mile Creek; Berthoud Pass; Irwin Lakes (A. H. Howell, loc. cit.) not found. Ochotona princeps schisticeps (Merriam). 1889. Lagomys schisticeps Merriam, N. Amer. Fauna, 2:11, October 30, type from Donner, Placer County, California. 1936. Ochotona princeps schisticeps, A. H. Miller, Jour. Mamm., 17:174, May 18. 1897. Ochotona schisticeps Merriam, Mazama, 1:223, October. Marginal records.—Nevada (Hall, 1946:590): 12 mi. E and 3 mi. N Ft. Bidwell, 5700 ft.; 8400- 8600 ft., Duffer Peak, Pine Forest Mts. California (A. H. Howell, 1924:39): Tahoe; Donner Pass; 12 mi. NE Prattville; Lassen Peak; Mt. Shasta. Ochotona princeps septentrionalis Cowan and Racey. 1947. Ochotona princeps septentrionalis Cowan and Racey, Canadian Field-Nat., 60:102, March 17, type from 6500 ft., Itcha Mountains, 52° 45´ N lat., 125° W long., British Columbia. Known from type locality only. Ochotona princeps sheltoni Grinnell. 1918. Ochotona schisticeps sheltoni Grinnell, Univ. California Publ. Zool., 17:429, April 25, type from 11,000 ft., "near" Big Prospector Meadow, White Mountains, Mono County, California. 1946. Ochotona princeps sheltoni, Hall, Mammals of Nevada, p. 593, July 1. Marginal records.—Nevada: 8700 ft., Pinchot Creek (Hall, 1946:593). California: type locality. Ochotona princeps taylori Grinnell. 1912. Ochotona taylori Grinnell, Proc. Biol. Soc. Washington, 25:129, July 31, type from 9000 ft., Warren Peak, Warner Mts., Modoc Co., Calif. Marginal records (V. Bailey, 1936:113, unless otherwise noted).—Oregon: N end of Steens Mts.; Guano Valley; Jack Lake, 20 mi. NE Adel; Adel. California (A. H. Howell, 1924:40): type locality; 5400 ft., "near" Termo, Madeline Plains; nr. head Little Shasta Riv. Oregon: Lower Klamath Lake. Ochotona princeps tutelata Hall. 1934. Ochotona princeps tutelata Hall, Proc. Biol. Soc. Washington, 47:103, June 13, type from 8150 ft., Greenmonster Canyon, Monitor Mts., Nye County, Nevada. Marginal records (Hall, 1946:591).—Nevada: 7500 ft., Smiths Creek, Desatoya Mts.; 8600 ft., type locality; 8700-11,000 ft., SW and W slopes Mt. Jefferson, Toquima Range; South Twin River; Arc Dome. Ochotona princeps uinta Hollister. 1912. Ochotona uinta Hollister, Proc. Biol. Soc. Washington, 25:58, April 13, type from "near" head E. Fork Bear River, Uinta Mts., Utah. 1924. Ochotona princeps uinta, A. H. Howell, N. Amer. Fauna, 47:19, September 23. [Pg 133] Marginal records.—Utah: type locality; Elk Park (Hall and Bowlus, 1938:337); 11,000 to 11,500 ft., The Nipple (ibid.); 10,500 ft., SW slope Bald Mtn. (op. cit.:336); Mt. Timpanogos (op. cit.:337); 8500 ft., Morehouse Canyon, 5 mi. above Weber River (op. cit.:337); Spirit Lake (op. cit.:336) not found. Ochotona princeps utahensis Hall and Hayward. 1941. Ochotona princeps utahensis Hall and Hayward, Great Basin Nat., 2:107, July 20, type from 2 mi. W Deer Lake, Garfield County, Utah. Marginal records.—Utah: 9000 ft., Donkey Lake, Boulder Mtn. (Durrant, MS); type locality. Ochotona princeps ventorum A. H. Howell. 1919. Ochotona uinta ventorum A. H. Howell, Proc. Biol. Soc. Washington, 32:106, May 20, type from Fremont Peak, Wind River Mts., Fremont County, Wyoming. 1924. Ochotona princeps ventorum A. H. Howell, N. Amer. Fauna, 47:18, September 23. Marginal records.—Montana: Emigrant Peak (A. H. Howell, 1924:19); Beartooth Mts. (ibid.). Wyoming: 9600 ft., 19-1/2 mi. E and 4-1/2 mi. S Shell (20882 KU); head of Trappers Creek (A. H. Howell, 1924:19); Medicine Wheel Ranch, 28 mi. E Lovell (32919 KU); Needle Mtn. (A. H. Howell, 1924:19); Lake Fork (ibid.); 8450 ft., 17-1/2 mi. S and 6-1/2 mi. W Lander (37994 KU); Middle Piney Lake, "near" Stanley (A. H. Howell, 1924:19); Salt River, 16 mi. S Afton (Hall and Bowlus, 1938:337); Teton Pass (A. H. Howell, 1924:19). Idaho: Teton Canyon (Davis, 1939:349). Family Leporidae—Rabbits and Hares Hind legs longer than forelegs; ears longer than wide; frontal bone carrying supraorbital process consisting always of posterior arm and sometimes of anterior arm; rostrum wide; nasals not wider anteriorly than posteriorly; maxillae conspicuously fenestrated; jugal projecting less than half way from zygomatic root of squamosal to external auditory meatus (except in Romerolagus); pubic symphysis well marked; dental formula, i. 2/1, c. 0/0, p. 3/2, m. 3/3 (but m. 2/3 in Pentalagus of Liu Kiu Islands south of Japan); second upper maxillary tooth like third in form; last lower molar double; cutting edge of first upper incisor straight; mental foramen of mandible situated under first lower cheek-tooth. Females average larger than males in all members of this family. (See Orr, 1940:20.) The reverse is true in most other families of mammals. Hare is a name applied to any lagomorph whose young are born fully haired, with the eyes open, and able to run about a few minutes after birth. The young are born in the open, not in a nest. All of the species of the genus Lepus are hares. The species of leporids of all genera other than Lepus, in North America at least, are rabbits. Their young are born naked, blind, and helpless, in a nest especially built for them and lined with fur. Considering the degree of development of the young at birth, the gestation periods are about what a person would expect: 26 to 30 days in Sylvilagus and 36 to 47 days in Lepus (see Severaid, 1950:356-357). Vernacular names are misleading because the names jack rabbit and snowshoe rabbit are applied to hares; also, Belgian hare is a name applied to a rabbit (genus Oryctolagus) that is commonly bred in captivity. There are many domestic strains and varieties of Oryctolagus and the animals are second only to poultry in some areas as a protein food for man. Also, the pelts are sold as a source of felt and many of the skins are dyed and processed for making fur coats and other fur-pieces that appear on the market under names not readily associated with rabbit. Rabbits and hares are crepuscular and possibly more nocturnal than diurnal. So far as I know they do not store food as do their diurnal relatives, the pikas. Some leporids, however, have an unusual, and possibly unique, method of processing food: Two types of vegetable pellets are expelled from the anal opening of the digestive tract; the dark brownish pellets, from which the nutriments have been extracted, are feces, but the greenish pellets seem to be only slightly predigested foods which are re-eaten. Southern (1942:553), among others, has written about this. This system functionally resembles that in the ruminants where a cud of vegetation is returned to the mouth, from one part of the stomach, to be re-chewed and finally swallowed. Because the causative organism of a disease that decimates dense populations of small mammals, and some other kinds of vertebrates, was isolated first in leporids, this disease, tularemia, is more associated in the popular mind with rabbits than with other kinds of mammals. Actually, many kinds of mammals are quite as likely to have tularemia as are rabbits. Now that streptomycin is available, cases of tularemia in persons are easily cured. Key to Species of the Genera Sylvilagus and Romerolagus 1. Antorbital extension of supraorbital process more than 1/2 length of posterior extension; first upper cheek-tooth with only one re-entrant angle on anterior face; re-entrant angle of second upper cheek- tooth not crenate Sylvilagus idahoensis, p. 139 1´. Antorbital extension of supraorbital process less than 1/2 of posterior extension or entirely absent; first [Pg 134] [Pg 135] upper cheek-tooth with more than one (usually 3) re-entrant angles on anterior face; re-entrant angle of second upper cheek-tooth crenate. 2. Anterior extension of supraorbital process absent (or if a point is barely indicated, then 5/6 or all of posterior process fused to braincase). 3. Tympanic bulla smaller than foramen magnum; hind foot more than 74; geographic range wholly in United States. 4. Ear more than 58 from notch in dried skin; basilar length of skull more than 63 Sylvilagus aquaticus, p. 166 4´. Ear less than 58 from notch in dried skin; basilar length of skull less than 63. 5. Underside of tail white; posterior extension of supraorbital process tapering to a slender point, this point free of braincase or barely touching it and leaving a slit or long foramen Sylvilagus transitionalis, p. 160 5´. Underside of tail brown or gray; posterior extension of supraorbital process always fused to skull, usually for entire length but in occasional specimens there is small foramen at middle of posterior extension of supraorbital process Sylvilagus palustris, p. 147 3´. Tympanic bulla as large as foramen magnum; hind foot less than 74; geographic range limited to southern edge of Mexican tableland at high elevations Romerolagus diazi, p. 138 2´. Anterior extension of supraorbital process present, and posterior extension free of braincase or leaving a slit between the process and braincase. 6. Tympanic bullae large (see fig. 26). Sylvilagus audubonii, p. 162 6´. Tympanic bullae small (see figs. 23, 25 and 27). 7. Restricted to Pacific coastal strip from Columbia River south to tip of Baja California, west of Sierra Nevada-Cascade Mountain Chain; hind foot less than 81. Sylvilagus bachmani and S. mansuetus, pp. 143, 147 7´. East of the Pacific coastal strip mentioned in 7; hind foot usually more than 81. 8. If north of United States-Mexican boundary: 9. In Arizona, New Mexico and southern Colorado posterior extension of supraorbital process free of braincase, and supraoccipital shield posteriorly pointed; from central Colorado north into Canada diameter of external auditory meatus more than crown length of last three cheek-teeth Sylvilagus nuttallii, p. 161 9´. In Arizona, New Mexico and southeastern Colorado posterior extension of supraorbital process of frontal with its tip against, or fused to, braincase, and supraoccipital shield posteriorly truncate or notched; from central Colorado north into Canada, diameter of external auditory meatus less than crown length of last three cheek- teeth Sylvilagus floridanus, p. 154 8´. If south of United States-Mexican boundary: 10. Geographic range restricted to Tres Marias Islands Sylvilagus graysoni, p. 169 10´. Geographic range not including Tres Marias Islands. 11. Underside of tail dingy gray or buffy (not white). 12. Tail short (less than 30) and brown like rump; ear from notch (dry) less than 53; interorbital breadth less than 16. Sylvilagus brasiliensis, p. 141 12´. Tail of moderate length (more than 30) and dingy gray; ear from notch (dry) more than 53; interorbital breadth more than 16 Sylvilagus insonus, p. 168 11´. Underside of tail distinctly white. 13. Total length more than 476; ear from notch (dry) more than 64; interorbital breadth usually more than 19.3; geographic range, southwestern Mexico north of the Isthmus of Tehuantepec. Sylvilagus cunicularius, p. 169 13´. Total length less than 476; ear from notch (dry) less than 64; interorbital breadth usually less than 19.3; geographic range, Canada to Panamá Sylvilagus floridanus, p. 154 Genus Romerolagus Merriam—Volcano Rabbit 1896. Romerolagus Merriam, Proc. Biol. Soc. Washington, 10:173, December 29. Type, Romerolagus nelsoni Merriam = Lepus diazi Diaz. Total length 300 to 311; tail rudimentary; hind foot, 52; ear from notch (dry), 36; upper parts grizzled buffy brown or dull cinnamon brown; underparts dingy gray; anterior projection of supraorbital process absent; jugal projecting posteriorly past squamosal root of zygomatic arch more than half way to external auditory meatus. The two cranial characters mentioned are resemblances to pikas although the skull otherwise resembles that of the true rabbits. The genus contains only the one living species. Living in well defined runways in the dense sacoton grass, these small rabbits are mainly nocturnal and crepuscular, but sometimes are active by day, especially in cloudy weather in the period of mating. Fig. 6. Distribution of Romerolagus diazi. Romerolagus diazi (Diaz) Volcano Rabbit 1893. Lepus diazi Diaz, Catal. Com. Geográf.-Expl. Repub. Mex. Expos. Internac. Columb. Chicago, pl. 42, March, 1893, type from eastern slope of Mount Ixtaccihuatl, Puebla. 1911. Romerolagus diazi Miller, Proc. Biol. Soc. Washington, 24:228, October 31, 1911. 1896. Romerolagus nelsoni Merriam, Proc. Biol. Soc. Washington, 10:173, December 29, 1896, type from west slope Mount Popocatepetl, 11,000 feet, México. Range.—Canadian Life-zone of the mountains bounding the eastern, southern and western sides of the Valley of Mexico. Marginal records.—México: Monte Río Frío, 45 km. ESE Mexico City (Davis, 1944:401). Puebla: type locality. México: Mt. Popocatepetl (Nelson, 1909:280). Distrito Federal: 31 km. S Mexico City (30815 KU). México: Llano Grande, 3 km. W Tlalmanalco (28278 KU). Genus Sylvilagus Gray—Cottontails and Allies Revised by Nelson, N. Amer. Fauna, 29:58-158, August 31, 1909. 1867. Sylvilagus Gray, Ann. and Mag. Nat. Hist., 20 (ser. 3):221. Type, Lepus sylvaticus Bachman, Lepus nuttalli mallurus Thomas. Total length, 291-538; tail, 18-73; hind foot, 71-110; ear from notch (dry) 41-74. Grayish to dark brownish above and lighter below; sutures of interparietal bone distinct throughout life; second to fourth cervical vertebrae broader than long with dorsal surface flattened and without carination. The delectable flesh of members of this genus, the large numbers that occur on a small area, even in thickly settled rural areas, and the wariness that rabbits soon develop when much hunted, give them top ranking among small game mammals. Tens of thousands of cottontails in Kansas and Missouri (Sylvilagus floridanus and some S. audubonii) are [Pg 137] [Pg 138] captured alive, transported to the eastern United States and released there to bolster the local supply of game. Considering that certain ectoparasites are limited to certain hosts and that some ectoparasites transmit such diseases as Rocky Mountain Spotted Fever whereas other ectoparasites do not, this transplantation of rabbits is dangerous. Also, expenditure of $100.00 on improving the habitat for Sylvilagus in a given area in the eastern United States would produce more cottontails than the expenditure of the same sum for live animals, from the Middlewest, that are to be released (see Langenbach and Beule, 1942:14, 15 and 30). Different species venture different distances from cover to feed. The Audubon cottontail of west-central California ventures a hundred feet and more from cover but the brush rabbit was never seen (Orr, 1940:182) farther than 42 feet from cover. In the thirties, when a gladiolus farmer from the chaparral belt of Santa Clara County, California, visited the University of California seeking advice on how to prevent damage by "cottontails" to his gladioli plantings, we asked the farmer if brush rabbits or cottontails were responsible and suggested to the farmer, who was unable to distinguish between the two, that an animal be killed and submitted for identification. When this was done, the brush rabbit (Sylvilagus bachmani) was found to be responsible for the damage. Robert T. Orr's recommendation that the chaparral (brush) be cut back 45 feet from the gladioli plantings was reluctantly followed and proved to be effective. A letter from a Santa Clara County agricultural official a couple of years later expressed thanks for the recommendation made by Orr, and estimated that adoption of his recommendations saved farmers of that one county $40,000 annually. This incident illustrates how detailed knowledge of the life history of a given kind of animal and control of its environment, rather than direct "control" of the animal, is sometimes of value to man. The genus Sylvilagus is restricted to the New World; the two species Sylvilagus brasiliensis and S. floridanus are the only two which occur in South America and they occur also in North America. Subgenus BRACHYLAGUS Miller—Pigmy Rabbit 1900. Brachylagus Miller, Proc. Biol. Soc. Washington, 13:157, June 13. Type, Lepus idahoensis Merriam. For characters see subgenus Sylvilagus. Sylvilagus idahoensis (Merriam) Pigmy Rabbit 1891. Lepus idahoensis Merriam, N. Amer. Fauna, 5:76, July 30, type from head of Pahsimeroi Valley, near Goldburg, Custer County, Idaho (Davis, Recent Mammals of Idaho, p. 363, April 9, 1939). 1930. Sylvilagus idahoensis, Grinnell, Dixon and Linsdale, Univ. California Publ. Zool., 35:553, October 10. Marginal records.—In southeastern Washington: Ritzville (Taylor and Shaw, 1929:29); Lind (243344 USBS); Warden (Taylor and Shaw, 1929:29). In remainder of range: Montana: Bannack (Davis, 1937:27). Idaho: Trail Creek near Pocatello (Davis, 1939:366). Utah: 3 mi. NE Clarkson (Durrant, MS); W side Utah Lake (ibid.); 20 mi. W Parowan (ibid.); 10 mi. SW Cedar City (ibid.). Nevada: 8-1/2 mi. NE Sharp (Hall, 1946:618); Fallon (Schantz, 1947:187). California: Bodie (Severaid, 1950:2); 5000 ft., 3 mi. S Ravendale (Orr, 1940:194). Oregon: Silver Lake (Bailey, 1936:110, fig. 17, 206518 USBS); Fremont (ibid., 205005 USBS); Redmond (ibid., 242302 USBS); 10 mi. N Baker (Dice, 1926:27). Idaho: type locality; Junction (Davis, 1939:366). Total length, 250-290; tail, 20-30; hind foot, 65-72; ear from notch (dry), 36-48; weight, 6 ♂ 409(375-435), 9 ♀ 398(246-458) grams. Upper parts pinkish to blackish or dark grayish depending on amount of wear. The pigmy rabbit lives in burrows, mostly dug by itself, preferably where tall sagebrush grows densely. This species feeds extensively on sagebrush, at least in winter. Six young seem to be the rule and they are born any time from late in May until early in August. [Pg 139] [Pg 140] Fig. 7. Distribution of Sylvilagus idahoensis. Subgenus SYLVILAGUS Gray—Cottontails and Allies 1867. Sylvilagus Gray, Ann. and Mag. Nat. Hist., 20 (ser. 3):221. Type, Lepus sylvaticus Bachman [= Lepus nuttalli mallurus Thomas]. 1867. Tapeti Gray, Ann. and Mag. Nat. Hist., 20 (ser. 3):224, September. Type Lepus brasiliensis Linnaeus. 1897. Microlagus Trouessart, Catalogus Mammalium ..., p. 660. Type, Lepus cinerascens J. A. Allen. 1897. Limnolagus Mearns, Science, n. s., 5:393, March 5. Type Lepus aquaticus Bachman. 1950. Paludilagus H...