BASTERIA, 59: 31-64, 1995 Observations onthe genus Mastus from Crete (Greece), with descriptions oftwelve newspecies (Gastropoda Pulmonata:Buliminidae) W.J.M. Maassen Azaleahof25,NL 1115 DH Duivendrecht, theNetherlands In challengingthe viewthat only twospeciesofthe genusMastusoccur inCrete, itis demon- strated thatthis genusisvery specioseon theislandinstead. Anidentificationkey is presented and 12 new species are described, emphasizing that several more await description. Conchologicallythesespeciesmaybe almostindistinguishable,but thestructureofthe genitalia enablestheiridentification.In severalareasmorethana singleMastus speciesis represented. Key words: Gastropoda,Pulmonata,Buliminidae,Mastus,taxonomy, Greece, Crete. INTRODUCTION During atrip to the GreekislandofCrete, in April 1987,a considerablenumberof shells as well as living specimens belonging to the genus Mastus Beck, 1837, were collected.Examinationofthismaterialprovided such interestingresults, thatfour more collecting trips were made, viz. in April 1990, October 1991, October 1992, and January 1993,in order to collect additionalmaterial. Some furtherresearch material wasprovided by a number ofcolleagues. Since the description of the two nominaltaxa Bulimus olivaceus and B. cretensisby L. Pfeiffer (1846), there has always been disagreement in the literature about the tax- onomicstatus ofthe CretanMastustaxa. Mostoften only a single species, M. cretensis, was accepted asvalidandM. olivaceus was considereda variety or atbest asubspecies of it. Heller (1976) was the first to consider M. cretensis and M. olivaceus specifically different,s.n. M.pupa cretensisand M. olivaceus, respectively. In hismaterial he noticed thatthese two taxa occur together at several localitieswithout intermediates. Anatomicalstudies by the present author show the existence ofconspicuous differ- encesingenital structures betweenmanyMastuspopulations, whichdifferencesare only partly associated with obvious conchological characters. Because these anatomical charactersproved tobe very uniformwithinand sometimesbetween populations, and because some formswere found sympatricallywith others withoutintermediates, itwas concluded that they represent different species, nearly all ofwhich turned out to be unnamed. Thispaperdeals withonly apart ofthe actually availablematerial.In additionto the twelve new species described hereafter, a considerable number ofstill other Mastus species appears toexist onthe island. Theseare not dealtwith here,because sufficient material for anatomicalstudies is not yet available. Some ofthese taxa belong to a separate complex, closely related to Mastus cretensis. These forms will be dealtwith elsewhere. Generaldistributionand ecology. — Ofall thespecies of the genus Mastus, M. pupa (Linnaeus, 1758) has the largest distribution: Spain (Sacchi, 1965; Seddon & Tat- 32 BASTERIA, Vol. 59,No. 1-3, 1995 tersfield, 1992), Algeria (Bourguignat, 1864, terra typica), Italy including the isles of Sicily, Malta and Lampedusa (Alzona, 1971), Tunisia (Letourneux & Bourguignat, 1887).TheislandsintheAegeanareaare inhabitedbya greaternumberofspecies. This groupis being studiedby Dr. R.A. Bank; the results will be published soon. A small number of species is also known from Turkey (fide Forcart, 1940): M. rossmaessleri (L. Pfeiffer, 1846),M. carneola(Mousson, 1863),M. etuberculata(Frauenfeld, 1867), and M.pontica (Retowski, 1887). Some other membersofthe genus are known from Russia [fide Shileyko, 1984: M.caucasica (L. Pfeiffer, 1854) and M. bielzi (Kimakowicz, 1890)], Rumania [fide Grossu, 1987: M. bielzi (Kimakowicz, 1890), M. transsylvanicus (Kimakowicz, 1890), M. venerabilis (L. Pfeiffer, 1855), and M. alpicola (Kimakowicz, 1890)], andBulgaria [fide Damjanov & Likharev, 1975:M. rossmaessleri (L. Pfeiffer, 1846) and M. carneola(Mousson, 1863). Mordan(1986: 210) classified also Buliminusomanensis Smith, 1894,withMastus. However, becauseofstriking anatomical and conchological differences, I prefer to consider this species from Oman not con- generic. This is in line with biogeographical considerations as well. Probably, a new genus has to be introducedfor it. The Cretanspecies liveonandinthe ground understones or wood,or hiddeninrock crevices. Especially during the dry and hot season, the animals seek protection well hiddeninthesoil, sometimes upto30 cm deep. Inspring, when theweatherisfar more humid, specimens were collectedwith full-grown shellsbut with their genitalia as yet undeveloped. Hence, all materialcollectedfromApriluntilthe second halfofOctober cannot be used for anatomicalinvestigations. The mating seasonstarts at about the second half ofOctober after the first rains and lasts until the end of February, as evidencedby thepresence ofspermatophores. The 1 orthe 10 km-grid UTM code is given with alllocalities mentioned. Conchological characters. — Itis hardly possible to give a conchological key, asthe shells ofthe Cretan Mastus species generally possess only few, if any, unequivocally diagnostic characters. The shells are dextral and vary in shape from long and very slender to short-ovoid.The outerandthe innerlip are usually connectedby a more or less prominent callus. In many species a well pronounced tubercle is present in the upperright cornerofthe aperture.Inseveral species thistubercle is obsolete, however. Theshellcolourvariesconsiderably, fromwhitish to darkbrown. In several species the surfaceofthe shellisalmostsmooth;inothers, thewhorlsareregularly striate, granulate or evenmalleate. The apical whorls are convex, whereas the lower ones are convexto almost flat. In most species the shells have a somewhatindented suture; when the growth-lines are thickened at their upperends, the suture becomes crenulated. Apart from size-differences there is not much variationin shell characterswithina single population, but among presumed species, these characters may vary considerably. Anatomicalcharacters. — According to Forcart(1940: 241) there are no differences ingeneral structure ofthe genitalia betweenspecies ofthegeneraChondrulaBeck, 1837, and MastusBeck, 1837.Thesetwo taxa are separated only onthe basis ofconchological characters. Species of Chondrula have shells with several well-developed teeth in the aperture,while in Mastus there is only a single more or less obsolete tubercle in the upper right (if dextral) orleft (ifsinistral) cornerofthe aperture. Maassen: Genus Mastus onCrete 33 Some general remarks concerning those parts of the genitalia that are used in this paper will not be repeated in the various species descriptions, which canbe relatively short and, therefore, more diagnostic. The terminology is for the greater part after Gittenberger & Menkhorst(1991). In all Cretan Mastusspecies studied, an atrium is hardly present. Withinthe penis there is a perforated papilla or verge, which occupies most ofthe lumenwhen full- grown. In all Cretan species butone, thisvergeis tapering ovally, only in M.gittenbergeri nov. spec, is it very flat. A short retractor muscle inserts laterally on the penis, at its distalend.The epiphallus is composed oftwoparts, separated by anepiphallic caecum. In most species theproximal andthe distalepiphallus haveadifferentlumenstructure. In several species the lumenofthe distalepiphallus shows some transverse folds (septa) close tothecaecum. Inmost cases theseseptacanbeseenfromtheoutsideinspecimens madetransparent. In onespecies (M. riedelinov. spec.) the septa are situated near the caecumin theproximal epiphallus. Thecaecumcanvary fromflatandobsoletetovery big, twice as long as the epiphallus is wide at this place (M. abundans).I. Usually the proximal epiphallus is more slender than both the penis and the distal epiphallus. Maybe the relative length ofthe distalpart ofthe epiphallus varies with age orsexual activity ofthe individualsin question. In the species studied there are two types of spermatheca. In the first type there is both arealbursaandadiverticulum.In thesecondtypethebursais missing; itsfunction is apparently taken over by the diverticulum. I do not agree with Mylonas & Var- dinoyannis (1989: 162), who claimthatthe absence ofa bursa is not a taxonomically important character. Inthespecies from Creteatleast, itisnotacaseofsimpleabsence. As amatter offact, only inthose species withoutany septa in theproximal part ofthe distalepiphallus, thebursa is missing. The morphology of the spermatophores was found to be an important taxonomic character in this group. Only in a few cases, if there are obvious diagnostic other characters, a new species is describedwithout data on the spermatophores. These provide informationonthe lumenstructure oftheepiphallus and flagellum (see below). Also in other groups of pulmonates, for example in milacid slugs (Wiktor, 1987), spermatophores have been found to provide excellent diagnostic characters. Inspecimens ofnineofthe twelve newspecies studied, I could findspermatophores, sometimes several, sometimes only some fragments. In these Cretan species a sper- matophore consists ofa distaland a proximal part, separated by definitionby the branching-off site ofa big hook, corresponding with the shape ofthe lumenin the caecum. The distal part is formed in the distal epiphallus and shows all kinds of ornamentation. The proximal part, formed in the proximal epiphallus, is smooth in most cases, curved and much shorterthan the distalpart. Two species groupscanbe distinguished onthe basis ofthe structure ofthe genitalia. In the firstgroup, the spermatheca has nobursa, and the spermatophore hasnospines butonly anumberoflongitudinal laminaealong the entirelength ofits distalpart. The second groupcontains species with a spermatheca provided with both a diverticulum andabursa, whereasthespermatophore hasspines. Mostprobably the spermatophores are produced only shortly before or during courtship, because only in one case a spermatophore (not yet completed and very fragile) was foundinside an epiphallus (in M. butoti). Probably this specimen was disturbedjust before or during mating. The majority of the undamaged spermatophores were found in the diverticulum of the spermatheca. In the bursa itself, only some fragments were found. Some snails had 34 BASTERIA, Vol.59, No. 1-3, 1995 Figs. 1,2.Schematicrepresentationofthe genitalia(1) andaspermatophore(2)ofMastusspecies.Abbreviations:A, atrium; B, bursa ofspermatheca; C, epiphalliancaecum; DB, duct ofthe bursa; DE, distal epiphallus; DI, diverticulum; DS, distalpart ofthespermatophore;FL,epiphallianflagellum;H,“hook” ofthespermatophore; OV,oviduct;P, penis;PED,pedunculus;PE, proximalepiphallus;PP,penispapilla;PR,penisretractormuscle; PS,proximalpart ofthespermatophore;SOD, spermoviduct;V, vagina;VD,vasdeferens. apparently mated several times within a short period oftime, because their sper- mathecae containedseveral more or less complete spermatophores, oneofwhich was undamaged and apparently fresh, andthe others partly dissolved. Remarks onthe geographic names used. — The spelling ofthe geographic names indicating the collecting localities is taken from the "Touristmap Crete", 1:80.000, issuedinfivepartsby HarmsVerlag, Erlenbach, Germany (1989-1993). On thesemaps some namesdifferfrom those usedon other maps. The most important examples are: Lenika (Ellinika), Sunias (Skinias), Xero Chorio (Xirohorio), Palekastro (Palaeokastro) and Stalida(Stalis). However, thisis themost complete seriesofdetailedCretan maps which are both readily available and very useful for an accurate description of the collecting site. Provisionalresults. — As mentionedabove, itwas hardly possible to characterize the species only by theirshells. However, as there are clearspecific anatomicaldifferences, itispossible to identifyatleastanumberofthe species whenalcohol-preserved material offull-grown animals is available. Apartfrom this, shell characters canbe interpreted betteras soonasanatomical datahave enabledspecies recognition. On the basis ofthe genital anatomy, the species describedbelowcanbe assigned to two clusters, characterizedby eitherthe presence or the absence ofa well-developed truebursaofthespermatheca. Species ofthesecond clusterweresofaronlyfound inthe eastern part ofCrete. Maassen: Genus Mastus onCrete 35 Thisstudyindicates thatapartfrom thealready describedM. cretensisandM. olivaceus, there are at least twelve other Mastustaxa, which I consider distinct species. These species are characterizedand formally described in this paper. As the identificationofMastus species requires specimens with fully developed geni- talia, which are found only in late autumn and winter, shells and alcohol-preserved immature specimens from a greatnumberoflocalities have to remain unnamed. Abbreviations.— For collectionsthe following abbreviationsare used: BU, L.J. M. Butot(Bilthoven); HE,J. Hemmen (Wiesbaden); IZPAN, Instytut Zoologniczy, Polska Akademia Nauk (Warszawa); KI, K. Kittel (Wiesthal); MA, W. J. M. Maassen (Dui- vendrecht); NE,W. H. Neuteboom (Heemskerk); RNMH, NationaalNatuurhistorisch Museum (formerly Rijksmuseum van Natuurlijke Historie) (Leiden); SU, P. Subai (Aachen); ZMA, Zoologisch Museum, Universiteit van Amsterdam. Shell height, H; breadth, B. Sample numbers are followedby the numberofspecimens in the sample, eithershells or, when ale. isadded,animals preserved in alcohol 70%. Acknowledgements. — We wish to thank L. J. M. Butot Bilthoven), Prof. Dr. E Gittenberger (Leiden),J. Hemmen(Wiesbaden), W. H. Neuteboom(Heemskerk), Prof. Dr. A.Riedel(Warszawa), andP. Subai(Aachen), whoenabledme tostudy thematerial in theircollections.A special debtofgratitude I owe toDr. R.A. Bank, who madethe photographs and both Dr. A. J. de Winterand Prof. Dr. E. Gittenberger for useful comments and corrections onthe manuscript. SYSTEMATIC PART Itis possible toidentify theknown species provisionally, using thefollowing key (after anatomicalcharacters). Key to the Cretan species ofMastus 1. Spermatheca bursa present 2 Spermatheca bursa absent 11 2. Penis retractor muscle inserting at the distalend ofthe penis 3 Penis retractor muscle inserting more proximally 5 3. Penis papilla flat M. gittenbergeri nov. spec. Penis papilla pointed 4 4. Epiphallus short; atleastsomeseptaarevisiblein its distalpart M.butotinov.spec. Epiphallus long; its distalpart withoutdistinct septa M. sitiensis nov. spec. 5. Distalpart ofthe epiphallus withoutdistinct septa 6 Distalpart ofthe epiphallus with such septa 8 6. Caecum inserting halfway the length ofthe epiphallus M. ierapetrana nov. spec. Caecum inserting more distally M. itanosensis nov. spec. 7. Genitalia small and very slender (fig. 13) M. sphakiota nov.spec. Genitaliamuch largerand robust 8 8. Bursa ductthick, almost as broad as the pedunculus M.procax nov. spec. Bursa ductslender 9 9. Bursa ductat least as long as the bursa itself 10 Bursa ductshort M. hemmeninov. spec. 36 BASTERIA, Vol.59,No. 1-3, 1995 10. Caecum clearly visible, epiphallus long and slender M. olivaceus (L. Pfeiffer) Caecum indistinct, epiphallus compact M. violacea nov.spec. 11. Proximal epiphallus with septa M. riedelinov.spec. Proximal epiphallus without septa 12 12. Epiphallic caecum very large (fig. 23) M. abundans nov.spec. Epiphallic caecummore orless normal 13 13. Genitaliavery small; distal epiphallus very compact (fig. 26) M. subaiinov.spec. Genitaliavery large; distal epiphallus less compact M. cretensis(L. PfeifTer) complex SPECIES DESCRIPTIONS 1. - Mastus gittenbergeri nov. spec. figs. 3, 4, 35, 49 Type material(all from Crete, Nomos Lasithiou). — Holotype: 2 km N. ofElounda, LV80 (RMNH 57064). Paratypes: locus typicus (MA/76, 21, 6, 43, 11 slides [nos. 604/606,979/981, 1073/1077], 5ale., 9 ale.; RMNH57081/5,57082/5,9427/9ale.; ZMA39005/5); N-side Elounda,LV80 (RMNH 57080/7); 1 km S. ofElounda,LV80 (MA/27, 2 slides [nos.1078/1079], 3 ale.); 2 km S. of Elounda, near Lenika, LU89 (MA/29, 5 slides [nos. 1080/1084], 9 ale.; RMNH 9428/6 ale.); 1 km E. ofLenika, rocky hill, E.ofthe road,LU89(RMNH 57079/7); 1 km SW. ofLenika,LU89 (RMNH 57078/1); 2.8 km S. ofElounda, hill, LV80 (HW/5, 2); 1.7 km SW. ofLenika, LU89 (BU/3); 1 km Lenika to Elounda, LV80 (BU/4; SU/6); Lenika near Elounda,LU89 (IZPAN/2); Elounda,LV80 (NE/1). Other material.— Nomos Lasithiou, 7 km S. ofElounda,LU89 (BU/1, 7). Diagnosis. — Shellslender, ofaverage size, with a somewhatgranular texture. The very flatpenis papilla is unlike that in any otherMastusspecies studied. Shell. — Shell of average size, slender, with 6-7 whorls, separated by a slightly indentedsuture. Apical whorlsconvex, theloweronesmoreflattened.Aperture broadly rounded, taking upto c. 30%ofthe totalshellheight. Asmall, inconspicuous, angular denticlepresent. Theshell isshining, lightpale-brown, sometimes nearly colourlessand transparent;the surfaceis covered with regular, somewhat granular striae. Dimensions: H 11.7-15.3 mm; B 4.7-5.4 mm. Holotype: 14.9x 5.2 mm Genitalia.— The genitalia are compact, not slender. The pedunculus ofthe sper- mathecais atleasttwiceaswide astheoviduct; thereisbothabursaandadiverticulum. The bursa is not well separated from its duct. The diverticulumhas about the same length as thepedunculus. Thepenis isaboutas long as the vagina. The penis retractor muscle inserts at the distalend of the penis. The distalpart ofthe epiphallus is much broaderthanthe proximal part.Acaecumis weakly developed. Thelumenstructure of the distalpart ofthe epiphallus, nearthe caecum, is composed ofabout six to eight conspicuous septa and three to four longitudinal folds. The lumen ofthe proximal epiphallus hasregular smallpapillae. Thepenispapilla is small, very flatandcomposed ofsmalltubercles. Theflagellum isveryshortandrounded.Thevasdeferensisvery thin and equally broad overits entire length. The spermatophore is unknown Derivatio nominis. — This species is named in honour of my friend, Prof. Dr. Edmund Gittenberger. He allowed metostudy theentire materialofthe genus Mastus Maassen: Genus Mastus onCrete 37 Figs. 3,4. Mastusgittenbergerinov. spec., 2km N.ofElounda. 3,genitalia;4,detailofthepenispapilla. kept in the Nationaal Natuurhistorisch Museum, Leiden, the majority ofwhich was collectedby himself. Observations. — This appearsto be the only Mastus species known with a flat penis papilla. It can be reported with certainty from a very restricted areabetween Plakain thenorthandAghios Nikolaosin thesouth.Alcoholmaterialcouldbestudiedonly from thecoastalarea; the distributionmoreinlandis stillunclear.Severalkilometresnorthof the type locality ofM. gittenbergeri, a large number ofpopulations are known of a conchologically very similarspecies, M. abundans.Anatomically thesetwo species can be separated easily, because in M. abundans the spermatheca is notprovided with a true bursa. SouthoftherangeofM.gittenbergeri, fromtheneighbourhood ofAghios Nikolaos, two additional, distinct species withsmallshellsareknown. Thesehaveto remainunnamed untilmore materialisavailablefor study. 2. - Mastus butotinov. spec. figs. 5-7, 35, 47 Type material(all from Crete, Nomos Irakliou). —Holotype: TobroukBeach, E. of Iraklion, LV31 (RMNH 57065). Paratypes: locus typicus (BU/33, 1 slide; MA/33, 1 slide [no. 967], 1 ale., 1 spermatophore; RMNH 57077/5); 1.8km E.ofIraklion, LV31 (BU/2); 1.2km E. ofIraklion, LV31 (BU/6); 1.4km S.of Tobrouk Beachto "Military camp", LV30 (BU/12); VathianosKampos, LV31 (MA/1, 6); 1 km W. ofVathianos Kampos, LV31 (HW/25;MA/45, 15ale., 2 slides [nos. 1037/1038]; RMNH 57083/5, 9429/5 ale.); 2 km VV. ofVathianos Kampos, LV31 (MA/1, 2 ale.); 2 km E. ofHani 38 BASTERIA, Vol. 59,No. 1-3, 1995 Kokkini, LV31 (MA/4, 7, 4ale., 2 slides[nos. 1041/1042]); AmnissosnearAg. Ioannis, LV31 (MA/73, 3 slides [nos. 797/799], 3 ale.; RMNH 57084/5; ZMA 394004/5; IZPAN/3); Prassas, LV31 (MA/5, 1 slide [no. 796]); 5km W.ofGournes,LV31 (SU/5; BU/3); Gournes, along the "New Road", LV41 (MA/7, 8); W. ofGouves, hill SW. of Hotel Marina, LV41(BU/36); KatoGouves, betweenHotel Marinaand "MainRoad", LV41 (BU/22); waste dump, S.ofGouves, 0.5 km N. ofexit to Skotino, LV40(BU/5); Skotino, LV40(MA/6, 5ale., 2 slides [nos. 1039/1040]); NE.ofGouves,LV41 (BU/4); 2km W. ofLiminHersonisou, LV51 (MA/12, 7,3, 3slides [nos. 968/969, 1043], 2 ale., 6 ale.; RMNH 9431/6 ale., 9414/1 spermatophore); along beach W. ofLimin Her- sonisou, LV51 (MA/9, 1 ale.). Other material(all from Crete, Nomos Irakliou): 5 km W. ofApostoli (9 km W. of Kastelli), LU49 (MA/10); AnoArchanes, Mt.Jouchtas, 200 malt., LV30(MA/9); Ano Archanes, Mt.Jouchtas, 500 m alt., LV30 (MA/2, HW/1, RMNH/1). Diagnosis. — Shell ovoid, small, with a malleate surface; aperture small. Sper- matheca with both a bursaand a diverticulum; penis retractor muscle inserting at the distal end ofthe penis; epiphallus short. Shell. — Shell small, ovoid, with 6.5-7.0 whorls, separated by somewhatindented sutures. Theapical whorlsconvex, thelower onesmoreor less flattened.Surfaceofthe protoconch whorls smooth, the adjoining ones more or less malleate, shining and provided withstrong but ratherirregular striae. The shellis widestat the body whorl. Aperture small, measuring c. 1/3ofthetotalshellheight, only a littlehigher thanwide (3.6 x 3.1 mm). Outerand innerlip connectedbya callus.Mostspecimens with asmall tubercle in the upperright corner ofthe aperture. Figs. 5-7. Mastusbutotinov.spec. 5,spermatophore,2km W.ofLimin Hersonisou;6,penis withspermatophore (black)inside, Skotino; 7, genitalia,Tobrouk Beach. Maassen: Genus Mastus onCrete 39 Dimensions: H 9.2-12.4 mm; B 4.1-4.8mm. Holotype: 10.4 x 4.5 mm. Genitalia.— Spermatheca with arelatively long diverticulum,whichisabout as long as the oviduct; its bursa is rounded and connected with the pedunculus by a much thinner duct. The vagina is shorter than the penis. The penis retractor muscle is attachedto thedistalend of thepenis. The epiphallus is about 1.5 times as long asthe penis. About half-way the epiphallus a prominent caecum is situated. The lumen structure oftheepiphallus hasa complicated patternoffoldsandpapillae. Laterally of the distalpartoftheepiphallus, justopposite thecaecum, thereare a numberofmoreor less prominent septa,corresponding to the spines onthe spermatophore. On the other side ofthe distal epiphallus the lumen structure is composed ofseveral longitudinal folds. The proximal epiphallus contains small papillae for about 2/3 ofitslength; the most proximal third, contacting the penis, has several longitudinal folds, which are devidedinto small lamellae.Where it enters the epiphallus, the vas deferens is dilated and has a lumen structure ofvery small papillae. Two spermatophores, fromspecimens collectedat differentlocalities, couldbe stud- ied. These turned outto be rather similar. They are c. 7 mm long and dividedinto a proximal and a distalpart by a big hook; this large protrusion is apparently moulded within the caecum. The distalpart bears a row ofabout 18 conspicuous spines; the initialspines are blunt, whereas the following onesare increasingly smallerand more acute towards the end. The proximal part ofthe spermatophore is much shorter, circular on cross-section anddevoidofany ornamentation. Derivatio nominis.— Thisspecies is namedaftermy friend, theDutch malacologist L.J.M.Butot (Bilthoven), who collected many samples of Mastus on Crete and over a long period oftimeallowed meto study these. Observations.— This species is limitedto the coastal area between Iraklionin the west and Limin Hersonisou in the east. Conchologically very similar populations are known from the hinterland.Shells from that areaare not consideredparatypes, how- ever, because noalcohol-preserved specimens wereavailable. At 2 km W. ofLiminHersonisou this species lives sympatrically with bothM. subaii and a species ofthe M. cretensis-complex. However, M. butoti is rather scarce at this locality, where M. subaii invery common. Conchologically, M.butotiismost similar toM.sitiensis, whichdiffersanatomically by alonger epiphallus, thecaecum notbeing situated half-way theepiphallus, andanother ornamentationof the spermatophore. M. sitiensis has a larger shell, the aperture of which has no tubercle. 3. - Mastus sitiensis nov. spec. figs. 8, 9, 35, 40 Typematerial(all fromCrete,Nomos Lasithiou). —Holotype: 5km E. ofAgia Fotia, E. of Sitia, MU29 (RMNH 57066). Paratypes: locus typicus (MA/39, 8 ale., 5 slides [nos. 1135/1139], 1 spermatophore; RMNH 57085/5, 9426/9 ale., 9424/1 sper- matophore; IZPAN/2;ZMA 394006/2); Sitia, MU19(IZPAN/24, 2 ale.); 1 km NE. of thecastle ofSitia,MU19(HW/6); nearBayofSitia, MU19(RMNH 52136/2); Petras, 2 km E. ofSitia, MU19(MA/18); hills, 3 km E. ofSitia, MU19 (MA/10); Agia Fotia, MU29 (MA/12, 4 ale., 6 slides [nos. 1126/1131]); 1 km E. of Agia Fotia, MU29 (MA/7); 7 km E. ofSitia, MU29 (HW/5); 3 km E. of Agia Fotia, MU29 (MA/1); Monastir Toplou, MU29(IZPAN/50, 3 ale.; MA/7, 1 slide [no. 1132]); ruin opposite 40 BASTERIA, Vol.59,No. 1-3, 1995 MonastirToplou, MU29(MA/2; NE/2); 1 km S. ofMonastirToplou, MU29(MA/13, 1 slide[no. 863]); 1 km W. ofMonastirToplou, MU29(MA/2); 3 km W.ofPalekastro, MU39 (SU/3; BU/10; MA/4); Palekastro, MU39 (IZPAN/3); 2 km S. ofPalekastro, MU39(RMNH 57121/2); 1 km N. ofPalekastro, MU39(MA/24, 5 ale., 2 slides [nos. 1133/1 134], 1 spcrmatophore; RMNH 57086/5, 9425/5 ale.). Other material (all from Crete, Nomos Lasithiou): 1 km from Roussa Ekklisia to Krioneri(= 6km SSE. ofSitia), MU29(HW/1);0.5km from Krioneri toPal. Mitato(= 8 km SSE. ofSitia), MU29 (HW/1); 3 km from Karidi to Adravasti (= 12 km SE. of Sitia), MU28 (HW/13); 3 km from KimouriotistoMonasirFaneromenis (4 km W. of Sitia), MU19 (HW/3); 1 km E. ofHandras, W. ofZiros, MU1882(RMNH/3); 1 km ENE. ofHandras, W. ofZiros, MU18(HW/3); AkrotiriFaneromenis, 5 km WSW. of Sitia, MU1495(RMNH/1); E. ofHamezi (8km WSW. of Sitia), MU1093(RMNH/2); Papagiannades, W. ofHandras, MU18(SU/1); 1 km N.ofMaronia, S. ofSitia, MU19 (MA/3); 1 km S. ofMaronia, MU19(HW/4); 1 km Piskokefalo to Ahladia, S. ofSitia, MU19(HW/1); 3.5km Piskokefalo toAhladia,S. ofSitia, MU19(HW/1); 3 km ESE. of Kato Zakros, MU3284 (RMNH/1); N-side of Kato Zakros, MU3284 (RMNH/2, HW/4, MA/1, 11, 4; NE/1); 2 km N. ofKato Zakros, MU28(MA/3); S-side ofKato Zakros, MU3284(RMNH/1); 0.5 km S. ofXerokambos, MU2977(RMNH/4); 1 km SW. ofXerokambos, MU37(HW/6);2 km NE. ofXerokambos, MU2979(RMNH/2); 7 km SSW. ofZakros, MU2678(RMNH/1); 4km SSE. ofZiros, MU2279(RMNH/3); 9 km W. ofXerokambos, MU27(NE/6); Nea Presos, 14km S. ofSitia, MU18(KI/1). Diagnosis. — Shell ofaverage size, elongate ovoid, fragile, with a fine spiral sculp- ture; aperture without a tubercle. Spermatheca with both a bursaand a diverticulum; penis retractor muscle inserting distally on the penis; epiphallus long, producing a spermatophore with a row oflittle, flattenedspines. Shell.— Shellmore orless fragile and somewhat translucent, of average size, ovoid, with 5.5 to 6.5 worls. The apical worls convex, the lower ones flattened.Shell surface Figs. 8, 9.Mastus sitiensisnov. spec., AgiaFotia.8,spermatophore;9, genitalia.