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 : 27-30

Dicharax (?) moellendorffi (Kobelt & Möllendorff, 1886)

FIGUrE 18 .

Alycaeus inflatus Möllendorff, 1886: 168 , pl. 5, fig. 7.

Alycaeus (Chamalycaeus) möllendorffi Kobelt & Möllendorff, 1897: 149 . (nomen novum pro inflatus Möllendorff, 1886 , non inflatus Godwin-Austen, 1874 )

Alycaeus (Chamalycaeus) moellendorffi — Kobelt, 1902: 359.

Chamalycaeus moellendorffi — Yen, 1939: 30, pl. 2, fig. 35.

Chamalycaeus (Chamalycaeus) moellendorffi — Zilch, 1957: 86 (4/6): 144, pl. 5, fig. 12.

Types examined. LECTOTypE SMF 39236, 2 paraLECTOTypEs SMF 39237, 8 paraLECTOTypEs SMF 39238, CHINa: DaUdsHOU (HUNaN) , COLL. MöLLENdOrff 1886, COLL. BOETTGEr; 3 paraLECTOTypEs SMF 39302, COLL. KObELT, samE daTa as prEvIOUs.

Museum material examined. SMF 109789 /2, CHINa, HUNaN, LEG . MöLLENdOrff, COLL. K.L. PfEIffEr, Ex COLL. JETsCHIN 1928 ; SMF 39240/1, HENG-dsHOU-fU (TsCHOU-fU), HUNaN: CHINa , COLL. O. BOETTGEr Ex COLL. GrEdLEr 1886 ; SMF 39239/2, PaTUNG, HUpEI, CHINa , COLL. O. BOETTGEr Ex COLL. GrEdLEr 1887 ; NHMUK 1891.3.17.786–787/2, HUNaN, LEG . HUNGErfOrd; NHMUK 1899.8.22.94–98/2, HUNaN ; NHMUK 20150481 /2, HUNaN , COLL. SykEs , 1954 ; NHMUK 20150482 /3, CHINa, HUNaN ; NHMW 41005 /2, HUNaN ; NHMW 40497 /10, HUNaN , COLL. MöLLENdOrff; NHMW 71640 /O/7351/1, HUNaN , COLL. ObErwImmEr Ex COLL. MöLLENdOrff.

Diagnosis. A mEdIUm sIzEd spECIEs wITH LONG R2 aNd R3, rEGULarLy rIbbEd R1 aNd R3, smOOTH R2 wITH THE NarrOw LIGHT aNd THICk dark TraNsvErsE sTrIpEs aLTErNaTE, aNd vEry sLIGHTLy CrENULaTEd pErIsTOmE.

Description. SHELL ( FIGUrE 18A ) LIGHT TaN; sHELL OUTLINE OvaL frOm dOrsaL vIEw, sHELL aLmOsT fLaT, EdGE Of bOdy wHOrL vEry sLIGHTLy aNGULaTEd, raTHEr “parabOLIC”; prOTOCONCH LOw, CONsIsTING Of 1.5 wHOrLs, aLmOsT smOOTH, GLOssy; R1 CONsIsTs Of 1.75 Or sLIGHTLy mOrE wHOrLs, rEGULarLy rIbbEd, rIbs bECOmE GradUaLLy LEss dENsE aNTErIOrLy; TraNsITION bETwEEN R1 aNd R2 abrUpT; LENGTH Of R2 + R3 sLIGHTLy mOrE THaN HaLf wHOrL; R2 aNd R3 Of abOUT THE samE LENGTH; R2 smOOTH ( FIGUrEs 18B–D ), wITH NarrOw LIGHT (= mICrOTUNNELs) aNd THICk dark (= arEa bETwEEN THE mICrOTUNNELs) TraNsvErsE sTrIpEs aLTErNaTE; ON SEM ImaGEs EdGE Of aNTErIOr CrUsT vIsIbLE as dOUbLE, paraLLEL LINE; CrOss-sECTIONaL vIEw Of R2 was ExamINEd IN ONE spECImEN (NHMW 40497, FIGUrE 18E , 68G ); aNTErIOr CrUsT ENTIrELy fLaT, ITs pOsTErIOr prOjECTION fOrms a mICrOTUNNEL wITH raTHEr ELLIpTICaL CrOss sECTIONaL vIEw wITH THE pOsTErIOr CrUsT; TraNsITION bETwEEN R2 aNd R3 CLEarLy vIsIbLE bECaUsE Of a CONspICUOUs CONsTrICTION; R3 wITH raTHEr IrrEGULar GrOwTH rIbs; apErTUrE ExTErNaLLy sLIGHTLy CrENULaTEd by HavING INCONspICUOUs kNOTs aNd sLIGHT UppEr INCIsION; OUTEr LIp sLIGHTLy rEfLECTEd aNd wIdENEd, INNEr LIp THICkENEd, THE bOUNdary bETwEEN THE TwO LIps CLEarLy vIsIbLE.

Measurements (in mm). D = 5.0–5.3, H = 2.7–2.8 (N = 3, SMF 39238).

Operculum. OUTEr sIdE mULTIspIraL, wITHOUT ELEvaTEd LamELLa; THE INNEr sUrfaCE Of THE OpENEd spECImEN (NHMW 40497) was ExamINEd, IT Is wITH a sTrONGLy ELEvaTEd, pOINTEd, CENTraL NIppLE.

Variation in specimens. THE ExamINEd spECImENs sHOwEd NO NOTabLE varIabILITy IN TErms Of sHELL CHaraCTErs.

Differential diagnosis. Dicharax moellendorffi CaN bE dIsTINGUIsHEd by aLL OTHEr CHINEsE aNd VIETNamEsE Dicharax spECIEs by THE smOOTH R2. SEE aLsO UNdEr D. cristatus .

Distribution. THIs spECIEs prObabLy INHabITs ONLy sOUTHErN HUNaN prOvINCE. THE HIsTOrICaL sampLEs wErE COLLECTEd frOm HUNaN aNd HUbEI prOvINCEs. THE LOCaLITy Of BadONG (HUbEI PrOvINCE) Is, HOwEvEr, prObabLy ErrONEOUs, THErEfOrE IT Is NOT INdICaTEd ON THE map ( FIGUrE 7 ).

Figures

FIGURE 7. Distribution of narrow range or single-site endemic Dicharax species. Filled circle. Dicharax tangmaiensis (Chen & Zhang, 2001). Filled triangle, top up. Dicharax (?) alticola Páll-Gergely & Hunyadi n. sp. Filled diamond. Dicharax (?) immaculatus Páll-Gergely n. sp. Empty diamond. Dicharax microcostatus Páll-Gergely n. sp., Dicharax micropolitus Páll- Gergely & Hunyadi, n. sp. and Dicharax bison Páll-Gergely & Hunyadi n. sp. Filled triangle, top down. Dicharax robustus Páll-Gergely & Hunyadi, n. sp. Empty triangle, top down. Dicharax draco Páll-Gergely & Hunyadi n. sp. Empty square. Dicharax imitator Páll-Gergely & Hunyadi n. sp. Empty triangle, top up. Dicharax (?) moellendorffi (Kobelt & Möllendorff, 1886). Filled square. Dicharax (?) ellipticus n. sp. Cross. Dicharax (?) abdoui Páll-Gergely n. sp. Empty circle shows the position of Tchen K’eou (Chengkou), which is the type locality of Alycaeus pentagonus Heude, 1886 (synonym of Alycaeus anthostoma Möllendorff, 1885), Dicharax diminutus (Heude, 1885), Dicharax (?) fargesianus (Heude, 1885), Dicharax planorbulus (Heude, 1885), Metalycaeus muciferus (Heude, 1885), Alycaeus dolomiticus Heude, 1890 (synonym of Alycaeus rathouisianus Heude, 1882), Dicharax (?) dolichodeiros (Heude, 1890), Metalycaeus (?) elevatus (Heude, 1886), Metalycaeus (?) expansus (Heude, 1890).

FIGURE 18. Dicharax (?) moellendorffi (Kobelt & Möllendorff, 1886). A. lectotype (SMF 39236). B – D. surface of R 2 (NHMW 40497). E. cross section of R 2 (NHMW 40497). All images: B. Páll-Gergely.

FIGURE 68. Schematic diagram of cross sections of R 2 of Dicharax and Metalycaeus species. The aperture opens leftwards. A. Dicharax bison Páll-Gergely & Hunyadi n. sp. B. Dicharax robustus Páll-Gergely & Hunyadi, n. sp. C. Dicharax fimbriatus (Bavay & Dautzenberg, 1912). D. Dicharax depressus (Bavay & Dautzenberg, 1912). E. Dicharax (?) alticola Páll- Gergely & Hunyadi n. sp. F. Dicharax (?) immaculatus Páll-Gergely n. sp. G. Dicharax (?) moellendorffi (Kobelt & Möllendorff, 1886). H. Metalycaeus muciferus (Heude, 1885). I. Metalycaeus oharai Páll-Gergely & Hunyadi n. sp. J. Metalycaeus (?) okuboi Páll-Gergely & Hunyadi, n. sp. Abbreviations: a: anterior crust; p: posterior crust; t: tunnel.