Dicharax micropolitus Asami 2017, n. sp.
Creators: name: Asami, Takahiro
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Architaenioglossa
Alycaeidae
Dicharax
Dicharax micropolitus

description: Dicharax micropolitus Páll-Gergely & Hunyadi n. sp.
FIGUrEs 34D, 42C–D, 43.
Type material. HOLOTypE HNHM 99709, OK/1 paraTypE, 20070709B CHINa, SICHUaN, TaIaN ZHEN, QINGCHENGHOUsHaN, DUjIaNGyaN SHI, CUIyINGHU TO UppEr sTaTION Of JINLI CabLE sTaTION, 1273 m, 30°56.27110'N, 103°28.75198'E, LEG. Y. NakaHara, K. OHara, K. OkUbO & J.U. OTaNI, 0 9 JULy 2007; HA/1 paraTypE, 2015/48 CHINa, SICHUaN, CHENGdU SHI, DUjIaNGyaN SHI, QINGCHENGHOUsHaN, UNdEr BaIzHaNG BrIdGE, 1220 m, 30°56.088'N, 103°28.818'E, LEG. A. HUNyadI & M. SzEkErEs, 0 5 JUNE 2015, JUO/1 paraTypE (INNEr sIdE Of THE OpErCULUm ObsErvEd wITH SEM), PGB/1 paraTypE (Ex COLL. JU. OTaNI, OUTEr sIdE Of THE OpErCULUm ObsErvEd wITH SEM), 2015060536 CHINa, SICHUaN, CHENGdU SHI, DUjIaNGyaN SHI, QINGCHENGsHaN ZHEN, QINGCHENGHOUsHaN, BaIyUN CUN, ImmEdIaTELy abOvE BaIzHaNGqIaO (brIdGE), 1262 m, 30°56.230'N, 103°28.749'E, LEG. A. HUNyadI, J.U. OTaNI, K. OHara, K. OkUbO & M. SzEkErEs.
Etymology. THE spECIfIC EpITHET rEfErs TO THE smaLL sIzE aNd smOOTH sHELL Of THIs NEw spECIEs.
Diagnosis. A smaLL spECIEs wITH smOOTH R1, ExTrEmELy sHOrT R2, sHOrT R3 wITHOUT swELLING aNd rOUNdEd pErIsTOmE.
Description. SHELL (FIGUrE 34D) LIGHT GrEENIsH brOwN; sHELL OUTLINE rOUNdEd frOm dOrsaL vIEw, spIrE sLIGHTLy ELEvaTEd, EdGE Of bOdy wHOrL rOUNdEd; prOTOCONCH (FIGUrEs 42C–D) LOw, CONsIsTING Of 1.5 wHOrLs, GLOssy; R1 CONsIsTs Of 1.75 wHOrLs, aLmOsT smOOTH, wITH ONLy vEry INCONspICUOUs, IrrEGULar GrOwTH LINEs; TraNsITION bETwEEN R1 aNd R2 vEry CLEarLy vIsIbLE; R2 vEry dENsELy rIbbEd, rIbs CUrvEd TOwards apErTUrE; CrOss-sECTIONaL vIEw Of R2 COULd NOT bE ExamINEd, bUT prObabLy sImILar TO THOsE Of THE OTHEr spECIEs HavING CUrvEd rIbs; COmbINEd LENGTH Of R2 aNd R3 sHOrT, apprOxImaTELy 70 dEGrEEs ONLy; R3 apprOxImaTELy fOUr TImEs LONGEr THaN R2; TraNsITION bETwEEN R2 aNd R3 CLEarLy vIsIbLE dUE TO CHaNGE Of sCULpTUrE, bUT NO CONsTrICTION vIsIbLE bETwEEN R2 aNd R3; swELLING ON R3 vEry bLUNT, NEarLy absENT; R3 smOOTH aNd GLOssy; apErTUrE ExaCTLy rOUNdEd, wITHOUT kNOTs Or CONspICUOUs UppEr INCIsION, bUT parIETaL rEGION adNaTE TO pENULTImaTE wHOrL; bOUNdary bETwEEN LIps HardLy vIsIbLE, INNEr LIp vEry wEak, OUTEr LIp vEry sLIGHTLy rEfLECTEd, EspECIaLLy IN dIrECTION Of UmbILICUs.
Measurements (in mm). D = 3.1–3.3, H = 1.9–2.2 (N = 3).
Operculum. STrONGLy CONvEx, OUTEr sIdE sEEmINGLy smOOTH, GLOssy, bUT apprOxImaTELy 5 wHOrLs arE CLEarLy vIsIbLE (FIGUrEs 43A–B); INNEr sIdE smOOTH, wITHOUT a NIppLE (FIGUrEs 43C–D).
Variation in specimens. THE fEw kNOwN spECImENs ExHIbIT LITTLE varIaTION IN sHELL mOrpHOLOGy.
Differential diagnosis. IN sIzE aNd sHELL sHapE Dicharax micropolitus n. sp. Is sImILar TO THE sympaTrIC D. microcostatus n. sp. THE dIffErENCEs arE THE fOLLOwING: R1 Is smOOTH IN D. micropolitus n. sp. bUT rIbbEd IN D. microcostatus n. sp.; R2 Is mUCH sHOrTEr IN D. micropolitus n. sp. THaN IN D. microcostatus n. sp.; R3 Is sHOrTEr IN D. microcostatus n. sp. aNd Has a CONspICUOUs swELLING NEar THE pErIsTOmE, bUT IT Is LONGEr aNd Has NO swELLING IN D. micropolitus n. sp. FUrTHErmOrE, THE pErIsTOmE Is rOUNdEd IN D. micropolitus n. sp. bUT sOmEwHaT CrENULaTEd IN D. microcostatus n. sp. THE COmbINaTION Of THE smaLL sHELL sIzE, THE sHOrT R2+R3 aNd THE CrENULaTEd pErIsTOmE dIsTINGUIsHEd D. micropolitus n. sp. frOm aLL CONGENErs. SEE aLsO UNdEr D. immaculatus n. sp.
Dicharax birugosus (GOdwIN-AUsTEN, 1893) frOm THE KHasI HILLs, INdIa (ExamINEd sampLE: NHMUK 1903.07.0 1.2628, 2 syNTypEs) Is sImILar TO D. micropolitus n. sp. IN TErms Of THE GLOssy R1 aNd R3, aNd THE sHOrT R2, bUT IT Has TwO LOw swELLINGs ON R2 aNd aN OvaL apErTUrE wITH CONspICUOUs LOwEr INCIsION. Dicharax duorugosus (GOdwIN-AUsTEN, 1914) frOm THE NaGa HILLs (maTErIaL ExamINEd: BUrraIL, COLL. GOdwIN-AUsTEN, NHMUK 1903.07.01.2771) aLsO pOssEssEs TwO bLUNT swELLING ON R3 aNd Has OvaL apErTUrE. AddITIONaLLy, D. duorugosus Has smOOTH R2 wITHOUT ELEvaTEd rIbs.
Distribution. Dicharax micropolitus n. sp. Is kNOwN frOm THrEE sITEs IN THE QINGCHENGHOUsHaN (praCTICaLLy a sINGLE pOpULaTION) (FIGUrE 7).
description: Published as part of Asami, Takahiro, 2017, Revision of the Alycaeidae of China, Laos and Vietnam (Gastropoda: Cyclophoroidea) I: The genera Dicharax and Metalycaeus, pp. 1-124 in Zootaxa 4331 (1) on pages 66-68, DOI: 10.11646/zootaxa.4331.1.1, http://zenodo.org/record/1009725