Dicharax cristatus
Creators: name: Asami, Takahiro
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Architaenioglossa
Alycaeidae
Dicharax
Dicharax cristatus

description: Dicharax cristatus (Möllendorff, 1886)
FIGUrEs 12C–D, 13C, 24–27, 28A–D, 29C–D, 30.
Alycaeus cristatus Möllendorff, 1886: 168, pl. 5, fig. 6.
Alycaeus (Charax) cristatus — Kobelt & Möllendorff, 1897: 150.
Alycaeus (Dicharax) cristatus — Kobelt, 1902: 367.
Alycaeus (Chamalycaeus) smithi Fulton, 1907: 157, pl. 10, fig. 5. new synonym Alycaeus (Charax) fimbriatus var. simplicilabris Bavay & Dautzenberg, 1912: 53 –54, pl. 6, fig. 18. new synonym. Dicharax cristatus — Yen, 1939: 30, pl. 2, fig. 39.
Chamalycaeus (Dicharax) cristatus — Zilch, 1957: 146, pl. 6, fig. 23. Chamalycaeus depressus — Do et al., 2015: 118, fig 1A.
Chamalycaeus heudei — Do et al., 2015: 118, fig 1C.
Chamalycaeus sp1.— Do et al., 2015: 118, fig 1E.
Types examined. LECTOTypE SMF 39231, 11 paraLECTOTypEs SMF 39232, 2 paraLECTOTypEs (SMF 39233) Of Alycaeus cristatus, Süd-HUNaN: CHINa, COLL. MöLLENdOrff 1886; 4 syNTypEs Of Alycaeus (Chamalycaeus) smithi (NHMUK 1907.5.3.137–140), MENGTzU, YUNNaN; 2 syNTypEs Of A. smithi (UMMZ 90166, pHOTOs rECEIvEd frOm Dr. TaEHwaN LEE), YüNNaN, CHINa, COLL. BryaNT WaLkEr Ex COLL. FULTON; MNHN IM-2012-27167 (TypE spECImEN, prObabLy HOLOTypE Of A. fimbriatus var. simplicilabris), MUONG-HUm, LEG. MEssaGEr.
Museum material examined. SMF 192410 /4 (UNdEr THE NamE smithi), CHINa: YUNNaN, COLL. C. BOsCH Ex COLL. H. ROLLE; SMF 39253/1 (wITH THE LabELs " intermedius " aNd anthostoma), MaNG-HaO, YüNNaN, CHINa, LEG. FULTON 1895; SMF 39234/2 (wITH vEry LOw swELLING ON R3 aNd THICk pErIsTOmE), Ta-TU-HO b. FU-LIN: SzECHwaN, CHINa, COLL. KrEjCI-Graf; SMF 39235/13 (wITH LOw swELLING ON R2), LU-HO, südL. LU-TIN-dsHOU, SzECHwaN, CHINa, COLL. KrEjCI- Graf; SMF 40271/1 (wITH sHOrT R3 aNd LOw swELLING), LU-TIN-dsHOU, SzECHwaN, CHINa, COLL. KrEjCI-Graf; SMF 39250/14 (mIxEd sampLE wITH M. helicodes: SMF 346399), PaTUNG, HUpEI, CHINa, COLL. MöLLENdOrff; SMF 40293/1 (LabELLEd as " monticola SCHmaCkEr & BOETTGEr"), ZaN-YaNG, 7000', CENTraL CHINa (THE CLOsEsT LOCaTION TO THaT CITy Of THaT ELEvaTION Is TaIbaI SHaN: 33°57'N, 107°46'E), LEG. S. YaNkOwsky, COLL. O. BOETTGEr; SMF 39251/2 (wITH smOOTH R3 wITHOUT swELLING), HUNaN Or HUpEI; SMF 346400 /6 (mIxEd sampLE wITH M. rathouisianus: SMF 39305), HUNaN, CHINa, COLL. MöLLENdOrff; NHMUK 1895.4.30.53–54/2 (LabELLEd as " intermedius SCHmaCkEr & BOETTGEr"), MENGTzU, YUNNaN; NHMUK 20150472 /2 (UNdEr THE NamE smithi), MENGTzU, YUNNaN, CHINa, E. SykEs COLL. 1954; NHMUK 20150473 /2 (LabELLEd as intermedius), YUNNaN, E.R. SykEs COLL. 1954; NHMUK 20150474 /2 (LabELLEd as plicilabris), HUNaN, CHINa, E.R. SykEs COLL. 1954; MNHN IM-2012-27040/6, MUONG-HUm, LEG. MEssaGEr; MNHN IM-2012-27041/3, MUONG-HUm, LEG. MEssaGEr; NHMUK 20150483 /2, TONkIN, MUONG-KUN, COLL. E. SykEs, 1954; MMGY/1, NO LOCaLITy; NHMUK 20150484 /1 (LabELLEd as simplex), TONkIN, E.R. SykEs COLL. 1954. SEE aLsO UNdEr REmarks.
New material examined. OK/1, 20060507D GaNsU, HUI XIaN, JIaNGLUO ZHEN, QINGHEyaNsUIdaO, 1189 m, 33°55.97072'N, 105°47.85497'E, LEG. K. OHara, K, OkUbO, & J.U. OTaNI, 0 7 May 2006; PGB/1 (Ex COLL. K. OHara), 20070712B CHINa, SICHUaN, QIONGLaI SHI, TIaNTaIsHaN ZHEN, TIaNTaIsHaN abOvE ZHENzHUpUbU, 30°16.87597'N, 103°07.46883'E, LEG. Y. NakaHara, K. OHara, K. OkUbO & J.U. OTaNI, 12 JULy 2007; OKA /1, PGB/1 (Ex COLL. K. OkUbO), 20070714A CHINa, SICHUaN, EmEIsHaN SHI, EsHaN ZHEN, EmEIsHaN, WaNNIaNsI, 865 m, 29°34.83012'N, 103°22.97325'E, LEG. Y. NakaHara, K. OHara, K. OkUbO & J.U. OTaNI, 12 JULy 2007; HA/2, 2015/71 CHINa, SICHUaN, LEsHaN SHI, EmEIsHaN SHI, EmEIsHaN, WaNNIaNsI, TEmpLE yard, 1000 m, 29°34.861'N, 103°22.882'E, LEG. A. HUNyadI & M. SzEkErEs, 17 JUNE 2015; PGB/1 (Ex COLL. K. OHara), 20070714B CHINa, SICHUaN, EmEIsHaN SHI, EsHaN ZHEN, EmEIsHaN, BaILONGdONG, 821 m, 29°34.73141'N, 103°23.32436'E, LEG. Y. NakaHara, K. OHara, K. OkUbO & J.U. OTaNI, 14 JULy 2007; JUO/2 sHELLs + ETHaNOL-prEsErvEd bOdIEs, 20130911B CHINa, SICHUaN, PaNzHIHUa SHI, MIyI XIaN, NINGHUa XIaNG, LONGTaN PUbU (waTErfaLLs), 1088 m, 27°00.035'N, 102°12.440'E, LEG. K. OHara, K. OkUbO & J.U. OTaNI, 11 SEp 2013; HA/3 wEaTHErEd sHELLs, 2015/57 CHINa, SICHUaN, PaNzHIHUa SHI, YaNbIaN XIaN, QINGHE PUbU, UppEr ENd Of THE waTErfaLL, 1650 m, 27°03.924'N, 101°23.884'E, LEG. A. HUNyadI & M. SzEkErEs, 0 9 JUNE 2015; HA/11+ 2 spECImENs IN ETHaNOL + radULa IN dOUbLE-faCEd adHEsIvE TapE, 2015/56 CHINa, SICHUaN, PaNzHIHUa SHI, MIyI XIaN, BaIma XIaNG, LONGTaN PUbU, ZHUaNxULONGdONG, 1610 m, 26°59.666'N, 102°12.521'E, LEG. A. HUNyadI & M. SzEkErEs, 0 8 JUNE 2015; OKA /1, PGB/1 (Ex COLL. K. OkUbO), 20040518A CHINa, YUNNaN, DaLIbaIzU ZIzHIzHOU, JIaNCHUaN XIaN, DIaNNaN, BIaNfUdONG, 2200 m, LEG. K. OkUbO, 18 May 2004; HA/15 (sOmE Of THEm arE wEaTHErEd), 2016/100 CHINa, CHONGqING, CHENGkOU XIaN, LaNTIaN XIaNG, mOUNTaIN abOvE LaUCI CUN (NOrTHErN sIdE), 1215 m, 31°55.399'N, 108°53.421'E, LEG. A. HUNyadI, 0 8 JUNE 2016; HA/2, 2016/ 103 CHINa, CHONGqING, CHENGkOU XIaN, DONGaN XIaNG, apprOx. 2 km sOUTH Of DONGaN, arOUNd GUaNyINyaN, 1140 m, 31°45.411'N, 109°05.636'E, LEG. A. HUNyadI, 0 9 JUNE 2016; HA/2, 2016/105 CHINa, CHONGqING, CHONGqING, CHENGkOU XIaN, QINGLONGxIa, ZHONGCHaNG, vaLLEy Of THE BaOxI HE, 1055 m, 31°49.918'N, 109°00.629'E, LEG. A. HUNyadI, 10 JUNE 2016; HA/1, 2016/108 CHINa, CHONGqING, CHENGkOU XIaN, HEyU XIaNG, 1200 m NOrTH frOm HEyU CUN TOwards WaNjIabaNG, YaNGHUzI, 1110 m, 31°52.906'N, 108°57.414'E, LEG. A. HUNyadI, 0 9 JUNE 2016; HA/1, 2016/109 CHINa, CHONGqING, CHENGkOU XIaN, HEyU XIaNG, 5 km NOrTH Of HEyU CUN, vICINITy Of CUOjIkOU, 1260 m, 31°54.286'N, 108°56.407'E, LEG. A. HUNyadI, 12 JUNE 2016; HA/5 (smaLL varIETy), 2016/114 CHINa, CHONGqING, CHENGkOU XIaN, YaNHE XIaNG, LUOHaNwUyI, NOrTHErN baNk Of THE CHaxI HE, 32°03.839'N, 108°24.122'E, LEG. A. HUNyadI, 14 JUNE 2016; HA/1, 2010/22 CHINa, HUbEI, YICHaNG SHI, ZIGUI XIaN, MaOpING SW 8 km, SIxI SHENGTaI FENGjINGqU, 345 m, 30°43.728'N, 110°54.751'E, LEG. A. HUNyadI, 30 OCT 2010; HA/2 sHELLs + 1 jUvENILE, 2010/13 CHINa, HUNaN, ZHaNGjIajIE SHI, ZHaNGjIajIE GUOjIa SENLIN GONGyUaN, TIaNzI SHaN JINGqU, ENvIrONmENT Of SHUaNGHEdONG, 925 m, 29°22.931'N, 110°27.438'E, LEG. A. HUNyadI, 24 OCT 2010; OKA /1, PGB/1 (Ex COLL. K. OkUbO), 20100509A CHINa, HUNaN, ZHaNGjIajIE SHI, WULINGyUaNqU, TIaNzIsHaN, SHUaNGHEdONG, 29°22.95'N, 110°27.45'E, LEG. K. OHara, K. OkUbO & J.U. OTaNI, 0 9 May 2010; OKA /16, PGB/3 (Ex COLL. K. OHara), PGB/1 (Ex COLL. K. OkUbO), 20100508A CHINa, HUNaN, ZHaNGjIajIE SHI, WULINGyUaNqU, GUaNyINdONG, 29°22.90'N, 110°36.80'E, LEG. K. OHara, K. OkUbO & J.U. OTaNI, 0 8 May 2010; JUO/2, OKA /2, PGB/1 (Ex COLL. K. OkUbO), 20100508B CHINa, HUNaN, CILI XIaN, SaNGUaNsITUjIazU XIaNG, ZHaNGjIajIEdaxIaGU, 29°24.00'N, 110°41.65'E, LEG. K. OHara, K. OkUbO & J.U. OTaNI, 0 8 May 2010; HA/2, 2010/7 CHINa, HUNaN, ZHaNGjIajIE SHI, TIaNmENsHaN GUOjIa SENLIN GONGyUaN, YIHONGGUaN (rOCks IN THE fOrEsT), 29°02.912'N, 110°28.616'E, LEG. A. HUNyadI, 22 OCT 2010; HA/3, 2010/18 CHINa, HUNaN, XIaNGxI TUjIazU MIaOzU ZIzHIzHOU, JIsHOU SHI, AIzHaI ZHEN, DEHaNG FENGjINGqU, YUqUaNxI JINGqU, bEGINNING Of THE GOrGE, 320 m, 28°20.611'N, 109°34.547'E, LEG. A. HUNyadI, 26 OCT 2010; OK/2, OKA /1, PGB/1 (Ex COLL. K. OkUbO), 20060109A CHINa, YUNNaN, WENsHaNzHUaNG ZUmIaOzU ZIzHIzHO, GUaNGNaN XIaN, LIjI, 1611 m, 23°45.54175'N, 104°59.55567'E, LEG. K. OHara, K. OkUbO & J.U. OTaNI, 0 9 JaN 2006; HA/6, 2011/20 CHINa, YUNNaN, WENsHaN ZHUaNGzU MIaOzU ZIzHIzHOU, GUaNGNaN XIaN, BabaO ZHEN, BabaO NE 1.5 km, LafaNG, 1138 m, 23°44.321'N, 105°25.304'E, LEG. A. HUNyadI, 24 Mar 2011; HA/ 4, 20 11 /22 CHINa, YUNNaN, WENsHaN ZHUaNGzU MIaOzU ZIzHIzHOU, GUaNGNaN XIaN, BabaO ZHEN, SaNLa, 1010 m, 23°45.350'N, 105°30.067'E, LEG. A. HUNyadI, 24 Mar 2011; PGB/1 (Ex COLL. K. OHara), 20111021 B CHINa, GUaNGxI, TIaNE XIaN, KaImU XIaNG, LaHaOyaN, 685 m, 24°50.993'N, 107°09.963'E, LEG. T. IsHIbE, K. OHara, K. OkUbO & J.U. OTaNI, 21 OCT 2011; OKA /1, PGB/1 (Ex COLL. K. OkUbO), 20150222A CHINa, GUaNGxI, HECHI SHI, TIaNE XIaN, KaImUzHEN, LaHaOyaN, LEG. K. OkUbO 22 FEb 2015; HA/11, 2013/7 CHINa, GUaNGxI, HECHI SHI, NaNdaN XIaN, CLIffs SE Of EN CUN, 630 m, 25°04.163'N, 107°36.176'E, LEG. A. HUNyadI & M. SzEkErEs, 11 SEp 2013; JUO/7, PGB/4 (Ex COLL. K. OHara), 20111020 A CHINa, GUaNGxI, NaNdaN XIaN, LIHUyaOzU XIaNG, EN CUN, GaNENdONG, 579 m, 25°04.270'N, 107°36.102'E, LEG. T. IsHIbE, K. OHara, K. OkUbO & J.U. OTaNI, 20 OCT 2011; HA/58 + 2 jUvENILE sHELLs, 2013/16 CHINa, GUaNGxI, HECHI SHI, HUaNjIaNG XIaN, CLIffs abOvE DONGNING VILLaGE S Of THE MULUN NaTUrE REsErvE, 530 m, 25°5.970'N, 107°57.639'E, LEG. A. HUNyadI & M. SzEkErEs, 17 SEp 2013; MAA3 CHINa, GUaNGxI, HECHI SHI, HUaNjIaNG XIaN, MULUN NaTUrE REsErvE (S-EdGE Of MaOLaN NaTUrE REsErvE, bOrdEr wITH GUIzHOU), LEG. T. WHITTEN, SEp 2004, WM/8; PGB/1 (Ex COLL. K. OHara), 20111019 E CHINa, GUaNGxI, HUaNjIaNGmaONaNzU ZIzHIxIaN, SHUIyUaN ZHEN, GUaNGNaN, 238 m, 24°49.217'N, 108°06.386'E, LEG. T. IsHIbE, K. OHara, K. OkUbO & J.U. OTaNI, 19 OCT 2011; PGB/2 (Ex COLL. K. OHara), 20100515B CHINa, GUaNGxI, GUILIN SHI, CaOpINGHUIzU XIaNG, GUaNyaN, 25°03.33'N, 110°26.88'E, LEG. K. OHara, K. OkUbO & J.U. OTaNI, 15 May 2010; HA/1 + 1 wEaTHErEd sHELL, 2009/70 CHINa, GUaNGxI, LaIbIN SHI, EasTErN EdGE Of XIaOpINGyaN, WUsHaN, 130 m, 23°24.351'N, 109°10.029'E, LEG. A. HUNyadI, 0 7 OCT 2009; HE/2, Vn 11-123 VIETNam, Hà GIaNG PrOvINCE, Ca. 7.5 km frOm ĐồNG VăN TO MèO VạC (rIGHT sIdE Off rOad), 23°14.906'N, 105°23.445'E, LEG. CH. HEmmEN, 23 Mar 2011; DDS/4+3, DDS1 VIETNam, SON La PrOvINCE, THUaN CHaU DIsTrICT, LImEsTONE karsT IN COpIa NaTUraL REsErvE, 1246 m, 21°21'25"N, 103°31'18"E, LEG. Đ. S Đỗ, 0 8 JUNE 2013; HA/2, 2012/60 VIETNam, SƠN La PrOvINCE, MộC CHâU 5 km TOwards SƠN La, rIGHT sIdE Of THE rOad NO. 6, 755 m, 20°52.551'N, 104°35.318'E, LEG. A. HUNyadI, 0 6 JUNE 2012; HE/17, Vn 12-104 VIETNam, SƠN La PrOvINCE, rIGHT sIdE Off rOad MộC CHâU TO SƠN La, 20°52.567'N, 104°35.310'E, LEG. CH. HEmmEN, 0 2 OCT 2012, HE/4, PGB/11 (Ex COLL. HEmmEN); samE LOCaLITy aNd COLLECTOr, 14.10.2011; HE/1, Vn 11-214 VIETNam, SON La PrOvINCE, Ca. 4 km frOm MOC CHaU TO MaI CHaU, 20°49.865'N, 104°40.556'E, LEG. CH. & J. HEmmEN, 15 OCT 2011; DDS/13, DDS6 VIETNam, SON La PrOvINCE, VaN HO DIs., VaN HO COm., LImEsTONE fOrEsTs IN Pa CHE VILL., 1050 m 20°47'07"N, 104°45'21"E, LEG. Đ.S. Đỗ, 26 OCT 2013; HA/1, 2012/61 VIETNam, SƠN La PrOvINCE, Hà N ộI 156 km TOwards MộC CHâU, LEfT sIdE Of THE rOad NO. 6, 1100 m, 20°45.993'N, 104°53.868'E, LEG. A. HUNyadI, 0 6 JUNE 2012; HA/2, 2012/ 62 VIETNam, SƠN La PrOvINCE, Hà N ộI 156 km TOwards MộC CHâU, rIGHT sIdE Of THE rOad NO. 6, 1100 m, 20°46.085'N, 104°53.888'E, LEG. A. HUNyadI, 0 6 JUNE 2012; JUO/10 + 2 jUvENILE sHELLs; samE daTa aNd COLLECTOr, JUO/15, PGB/1 (Ex COLL. J.U. OTaNI), 20080512C VIETNam, THaNH HOa PrOvINCE, NGOC LaC DIsTrICT, NGOC KHE COmmUNE, 81 m, 20°05.93390'N, 105°21.95595'E, LEG. K. OHara, K, OkUbO & J.U. OTaNI, 12 May 2008; PGB/1 (Ex COLL. K. OkUbO) (sTrONGLy wEaTHErEd sHELL, IdENTIfICaTION qUEsTIONabLE), 20090520A VIETNam, THaI NGUyEN PrOvINCE, VO NHaI DIsTrICT, PHU THUONG COmmUNE, PHUONG HOaNG CavE, MO Ga vILLaGE, 146 m, 21°46.836'N, 106°07.107'E, LEG. K. OHara & K. OkUbO 20 May 2009; MNHN IM-2012-27327 /2, 39L06 CENTraL LaOs, LUaNG PrabaNG PrOvINCE, apprOx. 1.5 km NE Of BaN Lak SIp, apprOx. 5 km SE Of LUaNG PrabaNG, PHOU XUaNG mOUNTaIN, UNdEr rOCks aNd LOGs IN OLd sECONdary fOrEsT UNdEr CLIff, 640 m, 19°51.605'N, 102°11.081'E, LEG. A. AbdOU & I.V. MUraTOv, 24 NOv 2004.
Diagnosis. A smaLL TO mEdIUm sIzEd spECIEs wITH TypICaL Dicharax -TypE rIbs ON R2, sHarp Or mOdEraTELy sHarp swELLING ON R3 (IN THE mIddLE Of R3, Or CLOsE TO THE apErTUrE) aNd IN mOsT CasEs rOUNdEd pErIsTOmE.
Description of the type series of cristatus. SHELL (FIGUrE 24A) IvOry; sHELL OUTLINE sLIGHTLy OvaL frOm dOrsaL vIEw, spIrE sLIGHTLy ELEvaTEd, EdGE Of bOdy wHOrL rOUNdEd; prOTOCONCH LOw, CONsIsTING Of 1.5–1.75, raTHEr maTTE wHOrLs; R1 CONsIsTs Of sLIGHTLy mOrE THaN 1.75 wHOrLs, raTHEr IrrEGULarLy, dENsELy rIbbEd; TraNsITION bETwEEN R1 aNd R2 NOT vEry CONspICUOUs, R2 sLIGHTLy mOrE dENsELy rIbbEd THaN R1; rIbs ON R2 CUrvEd TOwards THE apErTUrE, fOrmING aN OvEraLL NEarLy smOOTH sUrfaCE; LENGTH Of R2 + R3 LEss THaN a HaLf wHOrL LONG (apprOxImaTELy 130 dEGrEEs); R2 aNd R3 Of abOUT THE samE LENGTH; bOUNdary bETwEEN R2 aNd R3 INdICaTEd by a sHaLLOw CONsTrICTION; CONsTrICTION fOLLOwEd by raTHEr sHarp swELLING; rIbbING LEss dENsE ON R3 THaN ON R1 (wITH raTHEr IrrEGULar GrOwTH LINEs); apErTUrE rOUNdEd, wITHOUT kNOTs Or CONspICUOUs UppEr INCIsION; OUTEr LIp ONLy INdICaTEd, vEsTIGIaL, NOT rEfLECTEd, INNEr LIp sLIGHTLy THICkENEd. SEE rEmarks rEGardING THE fINE sTrUCTUrE Of THE R2 rIbs.
Measurements (in mm). D = 3.7–5.6, H = 2.1–3.5 (N = 60, sHELLs frOm sEvEraL sampLEs). SEE aLsO TabLE 1.
Operculum (FIGUrE 30). OUTEr sUrfaCE Is varIabLE: (1) COrNEOUs, mULTIspIraL, wITHOUT ELEvaTEd LamELLa (20100508A); OfTEN ONLy sOmE rEmaINs Of THE OUTEr LamELLa arE vIsIbLE NEar THE NUCLEUs aNd THE EdGE Of THE OpErCULUm (2006.01.09A; 1 OUT Of 2 sHELLs Had OpErCULUm); (2) wITH a wrINkLEd, rELaTIvELy LOw, raTHEr THICk, sTraIGHT, mULTIspIraL LamELLa (20130911B); (3) wITH aN ELEvaTEd, fINE, THIN, rEddIsH-brOwN LamELLa Of mULTIpLE wHOrLs; THIs LamELLa Is raTHEr smOOTH aNd sTraIGHT, LOwEsT NEar THE NUCLEUs aNd HIGHEsT NEar THE EdGE Of THE OpErCULUm, fOrmING a rELaTIvELy dEEp fUNNEL (MNHN IM-2012-27040: 2 OUT Of 6 spECImENs pOssEssEd OpErCULa; MNHN IM-2012-27041: 1 OUT Of 3 sHELLs Had OpErCULUm).
THE INNEr sUrfaCE Is smOOTH, wITH a LOw NIppLE ON ITs mIddLE (20100508A) Or wITH aN ELEvaTEd, pOINTEd NIppLE (20130911B).
Anatomy. ONE maLE spECImEN was aNaTOmICaLLy ExamINEd (20130911B, COLL. JUO). THE pENIs Is LarGE (sLIGHTLy LONGEr THaN THE rIGHT TENTaCLE) aNd pOINTEd (FIGUrEs 12C–D).
Radula. THE radULa Of ONE spECImEN was ExamINEd (2015/56, COLL. PGB, FIGUrE 13C). THE TEETH arE vEry sImILar TO THOsE Of Dicharax alticola n. sp. THE dIffErENCEs arE THE fOLLOwING: THE CUsps Of THE LaTEraL TEETH arE LONGEr aNd bLUNTEr; THE CUsps Of THE marGINaL TEETH arE sLIGHTLy mOrE sLENdEr.
Variation in specimens. Dicharax cristatus Is a varIabLE spECIEs IN TErms Of THE sHELL sIzE, THE spIrE HEIGHT (fLaT TO sOmEwHaT ELEvaTEd), pErIsTOmE (sTrONGLy CrENULaTEd TO NOT CrENULaTEd), THE sCULpTUrE Of R1 (smOOTH TO rEGULarLy rIbbEd), aNd THE prEsENCE/absENCE/pOsITION Of THE swELLING ON R3. THE INdIvIdUaL pOpULaTIONs LIsTEd UNdEr THIs spECIEs mIGHT bE vEry dIffErENT frOm EaCH OTHEr, bUT THEy arE CONNECTEd wITH a sErIEs Of INTErmEdIaTE fOrms. TabLE 1 COmpILEs THE varIabLE TraITs aNd THEIr CHaraCTEr sTaTEs IN ExamINEd pOpULaTIONs.
Differential diagnosis. MOsT Dicharax cristatus pOpULaTIONs dIffEr frOm D. moellendorffi by THE mOrE rOUNdEd sHELL sHapE, sHOrTEr R2, aNd sHOrTEr R3 wITH sHarpEr swELLING. MOsT ImpOrTaNTLy HOwEvEr, THE R2 Of D. moellendorffi Is smOOTH (ONLy dark aNd LIGHT TraNsvErsE sTrIpEs aLTErNaTE), wHErEas D. cristatus Has rIbs TypICaL TO Dicharax.
THE raNGE Of Dicharax fimbriatus aNd D. cristatus OvErLaps GrEaTLy, bUT THErE Is a sINGLE sITE wHErE THEy arE kNOwN TO LIvE IN sTrICT sympaTry (LOCaLITy COdE: 2011/20). THErEfOrE, THE TwO spECIEs arE NOT CONspECIfIC. ON THE OTHEr HaNd, NO sINGLE mUTUaLLy ExCLUsIvE TraITs CaN bE NamEd TO dIsTINGUIsH THEm dUE TO THE faCT THaT bOTH spECIEs arE varIabLE, INCLUdING sEvEraL LOCaL pOpULaTIONs wITH UNIqUE mOrpHOLOGICaL TraITs. GENEraLLy Dicharax fimbriatus Is CHaraCTErIzEd by a CrENULaTEd pErIsTOmE, wHICH Is rOUNdEd IN mOsT pOpULaTIONs Of D. cristatus. HOwEvEr, aLTHOUGH NO pOpULaTIONs Of D. fimbriatus arE kNOwN TO INCLUdE ONLy spECImENs wITH rOUNdEd apErTUrE, sOmE D. fimbriatus pOpULaTIONs INCLUdE spECImENs HavING rOUNdEd pErIsTOmEs. FUrTHErmOrE, sOmE D. cristatus pOpULaTIONs HavE CrENULaTEd pErIsTOmE. IN THOsE CasEs D. cristatus sHELL CaN bE dIsTINGUIsHEd frOm D. fimbriatus sHELLs ON THE basIs Of THE swELLING ON R3, wHICH Is sITUaTEd mUCH CLOsEr TO THE apErTUrE THaN IN D. fimbriatus. SEE aLsO UNdEr D. alticola n. sp., D. anthostoma, D. robustus n. sp., D. depressus, D. diminutus aNd D. fargesianus.
Distribution. Dicharax cristatus Is a wIdEsprEad spECIEs, wHICH Is kNOwN frOm GaNsU, SHaaNxI, SICHUaN, YUNNaN, HUNaN, HUbEI, GUaNGxI PrOvINCEs aNd NOrTHErN VIETNam.
Remarks. THE CrOss sECTIONaL vIEw Of R2 was ExamINEd IN ONE spECImEN (20111020 A, FIGUrEs 28C–D): aNTErIOr CrUsT fOrms a sIGNIfICaNTLy ELEvaTEd, HOLLOw rIb, wHICH Has a sTrONGEr aNTErIOr aNd wEakEr pOsTErIOr prOjECTION; aNTErIOr CrUsT fOLds sTrONGLy OvEr THE mUCH wEakEr pOsTErIOr CrUsT; pOsTErIOr CrUsT THICk, IT Is aLsO HOLLOw OCCasIONaLLy; CrOss sECTIONaL vIEw Of THE mICrOTUNNEL Is dEfOrmEd TEardrOp-sHapEd.
THE TypE sErIEs Of Alycaeus smithi (FIGUrEs 24B–C) dIffErs frOm THE LarGEr D. cristatus by THE dEEpEr CONsTrICTION aNd mOrE CONspICUOUs swELLING ON R3, mOrE wIdELy-spaCEd rIbs ON R1 aNd sHOrTEr R2. THEsE arE, HOwEvEr, ONLy mINOr dIffErENCEs aNd dO NOT aLLOw THE sEparaTION Of A. smithi frOm D. cristatus. MOrEOvEr, TypICaL cristatus aNd TypICaL smithi spECImENs arE CONNECTEd by INTErmEdIaTE fOrms. Alycaeus (Charax) fimbriatus var. simplicilabris (FIGUrE 27A) dIffErs frOm TypICaL Alycaeus cristatus by THE LarGEr sIzE, LOwEr swELLING ON R2, aNd THE sLIGHTLy CrENULaTEd pErIsTOmE. HOwEvEr, THEsE Taxa arE aLsO CONNECTEd by INTErmEdIaTE fOrms. THErEfOrE, A. smithi aNd A. fimbriatus var. simplicilabris arE syNONyms Of Dicharax cristatus.
THErE arE THrEE pOpULaTIONs (20111021 B: FIGUrE 27C, 2011/22: FIGUrE 27E, 2012/60: FIGUrE 27F) wITH LarGE sHELLs aNd a sHarp swELLING, wHICH Is sITUaTEd CLOsE TO THE pErIsTOmE. INITIaLLy wE CONsIdErEd THEm as a spECIEs sEparaTE frOm Dicharax cristatus, bUT wE rEjECTEd THIs pOssIbILITy, bECaUsE THE TypE spECImENs Of Alycaeus fimbriatus var. simplicilabris aNd sOmE TOpOTypIC spECImENs sHOw a pErfECT TraNsITION bETwEEN THE ONE frOm a bLUNT TO THE ONE wITH a vEry sHarp swELLING ON THE R3.
A sampLE CONTaINEd 6 sHELLs Of TypICaL A. simplicilabris (MNHN IM-2012-27040), aNd ONE sHELL Of D. fimbriatus (MNHN IM-2012-27044), aNd THErE wErE TwO smaLL LabELs, ONE wITH THE sCrIpT "MUONG-HUm" aNd THE OTHEr wITH "PaC-KHa". WE assUmE THaT THE D. fimbriatus sHELL was OrIGINaLLy frOm PaC-KHa, bECaUsE IT Is THE TypE LOCaLITy Of THE spECIEs, wHErEas THE D. simplicilabris sHELLs wErE COLLECTEd frOm MUONG-HUm, bECaUsE aNOTHEr sampLE Of THE spECIEs was aLsO COLLECTEd frOm THErE (sEE UNdEr MaTErIaL ExamINEd).
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 34-43, DOI: 10.11646/zootaxa.4331.1.1, http://zenodo.org/record/1009725