Dicharax, Kobelt & Mollendorff, 1900

Asami, Takahiro, 2017, Revision of the Alycaeidae of China, Laos and Vietnam (Gastropoda: Cyclophoroidea) I: The genera Dicharax and Metalycaeus, Zootaxa 4331 (1), pp. 1-124 : 107

Dicharax (?) tangmaiensis ( Chen & Zhang, 2001)

Chamalycaeus tangmaiensis Chen & Zhang, 2001: 184 –185, 188–189, figs 1–4.

Type locality. "TONGmaI TOwN, (30°01'N, 95°E), BOmI COUNTy, TIbET AUTONOmOUs REGION, CHINa ".

Original description. " SHELL smaLL, THICk, sUbdEprEssEd, sEmITraNparENT. WHOrLs 3½, mOdEraTELy CONvEx, spIrE LOw, CONOId, aNd THE prOTOCONCH aNd sECONd wITH LUsTrE, GENEraLLy smOOTH. SHELLs yELLOwIsH brOwN IN COLOUr, sUrfaCE wITH vEry fINELy aNd sOmEwHaT rEGULarLy rIb-sTrIaE, sUTUrE dEEp, aNd wITH a 0.56 mm prOjECTION as wOrmfOrmEd aT THE sUTUrE Of THE bOdy wHOrLs. UmbILICUs wIdE, rEGULarLy wIdENING, sHOwING THE EarLIEr wHOrLs INsIdE. ApErTUrE CIrCULar, THICk, wITH wavE-fOrmEd LOps, aNd a NECk. OpErCULUm CIrCULar, sINk, INNEr sUrfaCE Has a papULEfOrmEd prOjECTION."

Remarks. THIs spECIEs Is prOvIsIONaLLy pLaCEd IN THE GENUs Dicharax bECaUsE THE prOTOCONCH Is LOw, aNd THE rIbs ON R2 arE sEEmINGLy NOT sHarp.

IN THE OrIGINaL dEsCrIpTION Chamalycaeus tangmaiensis was COmparEd ONLy wITH Chamalycaeus diminutus , wHICH Is vEry dIffErENT by bEING mUCH smaLLEr, HavING a rOUNdEd pErIsTOmE aNd LaCkING a sHarp swELLING ON R3. FUrTHErmOrE, IT was OrIGINaLLy dEsCrIbEd aT LEasT 1300 km frOm THE TypE LOCaLITy Of Chamalycaeus tangmaiensis . WE wErE NOT abLE TO ExamINE Chamalycaeus tangmaiensis , bUT THE ILLUsTraTIONs IN THE OrIGINaL dEsCrIpTION prOvIdE ENOUGH EvIdENCE THaT IT dIffErs frOm aLL OTHEr CHINEsE ALyCaEIdaE . ON THE OTHEr HaNd, THErE arE a NUmbEr Of NOrTH- EasTErN INdIaN aNd BUrmEsE spECIEs, wHICH aGrEE wITH D. tangmaiensis IN THE fLaT sHELL, THE sTrONGLy CrENULaTEd pErIsTOmE aNd THE swELLING ON R3 sITUaTEd vEry CLOsE TO THE pErIsTOmE: Alycaeus crenatus GOdwIN-AUsTEN, 1871 (TypE LOCaLITy: "ON BUrraIL RaNGE, N. CaCHar, aT abOUT 5000 fEET"); Alycaeus cucullatus THEObaLd, 1870 (TypE LOCaLITy: " SHaN STaTEs"); Alycaeus daflaensis GOdwIN-AUsTEN, 1876 (TypE LOCaLITy: "TOrúpúTú PEak, 7000 fEET"); Alycaeus digitatus BLaNfOrd, 1871 (TypE LOCaLITy: "apUd DarjEELING IN vaLLO RUNGNO fLUmINIs HImaLayae SIkkImENsIs"); Alycaeus ochraceus GOdwIN-AUsTEN, 1893 (TypE LOCaLITy: "RUby MINEs DIsTrICT, UppEr BUrmaH"); Alycaeus plectocheilus BENsON, 1859 (TypE LOCaLITy: "IN vaLLE RUNGUN"). FUTUrE INvEsTIGaTION sHOULd fOCUs ON THE dIsTINCTNEss Of Chamalycaeus tangmaiensis frOm THE abOvE-mENTIONEd spECIEs.