Dicharax anthostoma (Möllendorff, 1885)

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 : 30-32

Dicharax anthostoma (Möllendorff, 1885)

FIGUrEs 19A–B .

Alycaeus anthostoma Möllendorff, 1885: 162 .

Alycaeus (Charax) anthostoma — Möllendorff, 1886: 166, pl. 5, fig. 4. Alycaeus pentagonus Heude, 1886: 211 , new synonym.

Alycaeus pentagonus — Heude, 1890: 129, Plate 36, fig. 18. Alycaeus (Charax) anthostoma — Kobelt & Möllendorff, 1897: 149. Alycaeus (Charax) pentagonus — Kobelt & Möllendorff, 1897: 150. Alycaeus (Dicharax) anthostoma — Kobelt, 1902: 364.

Alycaeus (Dicharax) pentagonus — Kobelt, 1902: 374.

Dicharax anthostoma — Yen, 1939: 30, pl. 2, fig. 38.

Chamalycaeus (Dicharax) anthostoma — Zilch, 1957: 145, pl. 6, fig. 22.

Types examined. LECTOTypE SMF 39225 aNd 12 paraLECTOTypEs ( SMF 39226 ) Of Alycaeus anthostoma , PaTUNG, HUbEI: CHINa , COLL. BOETTGEr Ex COLL. MöLLENdOrff; 3 paraLECTOTypEs Of A. anthostoma (MCZ 180902), CHINa, HUpé, COLL. MöLLENdOrff, Ex ObErwImmEr, Ex DavId D. THaaNUm, JaN. 1947 ; 2 syNTypEs Of A. pentagonus ( MCZ 167215 ), CHINa, TCHEN-k'EOU.

Museum material examined. SMF 39249/4, PaTUNG, HUbEI: CHINa , COLL. MöLLENdOrff; SMF 39227/5, CHaNGyaNG, HUpEI: CHINa, LEG. SCHmaCkEr 1893 , COLL. BOETTGEr; SMF 192352 /3, CHINa , COLL. C. BOsCH Ex COLL . H. ROLLE; SMF 109727 /2, CHINa: HUpEI , COLL. K. L. PfEIffEr Ex JETsCHIN Ex MöLLENdOrff; NHMUK 1891.4.24.57 – 60/4, CHaNGya, Ex COLL . CarL BOCk; NHMUK 20150469 /2, CHINa, HUpEH, E.R. SykEs COLL ., 1954; NHMUK 20150470/3, CHaNGyaNG, V.W. MaCANdrEw COLL.; NHMUK 20150471 /2, SECUsaN, CHINa, E.R. SykEs COLL. 1954 .

New material examined. HA/3, 2010/31 CHINa, HUbEI, ENsHI TUjIazU MIaOzU ZIzHIzHOU, BadONG XIaN, CHadIaNzIzHEN S, LIaNxIa FENGjINGqU, LIaNTOUCaO N, 1025 m, 30°53.544'N, 110°18.995'E, LEG. A. HUNyadI, 0 3 NOv 2010.

Diagnosis. A smaLL TO mEdIUm sIzEd spECIEs wITH TypICaL Dicharax - TypE rIbs ON R2, sHarp swELLING ON R3, LarGE dIsTaNCE bETwEEN THE TwO LIps Of THE pErIsTOmE, aNd sTrONGLy CrENULaTEd INNEr LIp.

Description of the type series of D. anthostoma . SHELL ( FIGUrEs 19A–B ) ECrU IN COLOUr; sHELL OUTLINE sLIGHTLy OvaL frOm dOrsaL vIEw, spIrE mOdEraTELy ELEvaTEd, bOdy wHOrL rOUNdEd; prOTOCONCH (1.75 wHOrLs Or sLIGHTLy LEss) LOw, aLmOsT smOOTH, GLOssy; R1 CONsIsTs Of 1.5–1.75 wHOrLs, fINELy, rEGULarLy rIbbEd (aLmOsT smOOTH IN sOmE spECImENs); rIbs vEry sLIGHTLy LEss dENsE NEar ENd Of R1; NO spIraL LINEs dETECTEd ON R1; TraNsITION bETwEEN R1 aNd R2 CLEarLy vIsIbLE bECaUsE Of INCrEasING dENsITy Of rIbs; LENGTH Of R2 + R3 LEss THaN a HaLf wHOrL (abOUT 150–160 dEGrEEs); R2 aNd R3 Of abOUT THE samE LENGTH; R2 vEry fINELy aNd dENsELy rIbbEd, rIbs CUrvEd TOwards THE apErTUrE; CrOss-sECTIONaL vIEw Of R2 COULd NOT bE ExamINEd bUT prObabLy sImILar TO THaT Of OTHEr spECIEs wITH CUrvEd rIbs ( D. depressus , D. fimbriatus , ETC.); TraNsITION bETwEEN R2 aNd R3 CLEarLy vIsIbLE bECaUsE Of a CONspICUOUs, dEEp aNd LONG CONsTrICTION bETwEEN R2 aNd R3; afTEr THE CONsTrICTION THErE Is a sHarp swELLING ON R3; R3 wITH raTHEr rEGULar, dENsE rIbs; apErTUrE ExTErNaLLy sTrONGLy CrENULaTEd; OUTEr LIp sHarp, sLIGHTLy rEfLECTEd, sITUaTEd dIsTaNT frOm THE INNEr LIp, wHICH Is sLIGHTLy THICkENEd, sTrONGLy CrENULaTEd.

Measurements (in mm). D = 3.7–5.3, H = 2.4–3.2 (N = 8, sHELLs frOm dIffErENT sampLEs).

Operculum. THE OUTEr sUrfaCE Of THE OpErCULUm was ExamINEd (LECTOTypE Of D. anthostoma aNd syNTypE Of D. pentagonus ). IT Is CONCavE, mULTIspIraL, bUT NO ELEvaTEd baNd Is vIsIbLE.

Variation in specimens. NO TraITs wErE fOUNd TO bE varIabLE wITHIN THIs spECIEs.

Differential diagnosis. Dicharax anthostoma Is CHaraCTErIzEd by THE LarGE dIsTaNCE bETwEEN THE TwO LIps Of THE pErIsTOmE. THIs TraIT dIsTINGUIsHEs IT frOm THE vEry sImILar D. fimbriatus . THE pErIsTOmE Of mOsT D. cristatus pOpULaTIONs Is NOT CrENULaTEd. SEE aLsO UNdEr D. fraterculus .

Distribution. ALL mUsEUm sampLEs wErE COLLECTEd frOm BadONG aNd CHaNGyaNG (bOTH EasTErN HUbEI PrOvINCE) aNd frOm TCHEN-k'EOU (NOrTHErN CHONGqING PrOvINCE). THE ONLy NEwLy COLLECTEd sampLE wE ExamINEd was COLLECTEd NEar BadONG CITy ( FIGUrE 20 ).

Remarks. THE sHELLs Of THE TypE sErIEs Of Alycaeus anthostoma aNd A. pentagonus sHOw NO dIffErENCEs; THErEfOrE THE LaTTEr Is pLaCEd IN THE jUNIOr syNONymy Of A. anthostoma .

Figures

FIGURE 19. Shells of Dicharax species. A. Dicharax anthostoma (Möllendorff, 1885) (lectotype, SMF 39225). B. Dicharax anthostoma (syntype of Alycaeus pentagonus, MCZ 167215). C. Dicharax robustus Páll-Gergely & Hunyadi, n. sp. (holotype, HNHM 99704). Scale represents 5 mm. All photos: B. Páll-Gergely.

FIGURE 20. Distribution of Dicharax species. Triangle. Dicharax anthostoma (Möllendorff, 1885). Circle. Dicharax fimbriatus (Bavay & Dautzenberg, 1912). 1. Tchen K’eou (Chengkou; type locality of Alycaeus pentagonus Heude, 1886 = synonym of Alycaeus anthostoma Möllendorff, 1885). 2. Badong (type locality of Alycaeus anthostoma Möllendorff, 1885). 3. 2010 / 31. 4. Changyang. 5. 2015 / 74. 6. 2011 / 12. 7. 20060108 A. 8. 20060108 D. 9. Pac Kha (type locality of Alycaeus fimbriatus). 10. DDS 7. 11. Ch 1. 12. 20060110 G. 13. 20060111 B. 14. 20060111 G. 15. 20041113 A. 16. 20111025 B. 17. 20130608 C. Empty, enumerated circles correspond with the localities of figured specimens.