Metalycaeus heudei (Bavay & Dautzenberg, 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 : 74-84

Metalycaeus heudei (Bavay & Dautzenberg, 1900)

FIGUrEs 49C–D , 50–52 , 53C–D .

Alycaeus (Charax) heudei Bavay & Dautzenberg, 1900a: 121 .

Alycaeus (Charax) heudei Bavay & Dautzenberg, 1900b: 458 –459, pl. 11, figs 15–18. Alycaeus (Dicharax) heudei — Kobelt, 1902: 372.

Alycaeus paviei Bavay & Dautzenberg, 1912: 50 –51, pl. 4, figs 5–8. new synonym. Alycaeus paviei var. minor Bavay & Dautzenberg, 1912: 51 , pl. 4, fig. 9. new synonym. Chamalycaeus nanus (partim, see remarks under D. nanus )— Jaeckel, 1950: 19. Chamalycaeus (Dicharax) compressicosta Zilch, 1957: 145 –146, fig. 33. new synonym. Chamalycaeus (Dicharax) fractus Varga, 1974: 165 –167, figs 1–5. new synonym. Alycaeus zhuangiyucuii Yang, Fan, Qiao & He, 2012: 32 , fig. 2. new synonym. Chamalycaeus paviei — Do, et al., 2015: 118, fig 1D.

Types examined. MNHN IM-2012-27169 (TypE spECImEN, prObabLy HOLOTypE Of heudei ), HaUT TONkIN, LEG. MEssaGEr ; MNHN IM-2012-27163 (TypE spECImEN, prObabLy HOLOTypE Of paviei ), BaN LaO, LEG. MEssaGEr ; MNHN IM-2012-27164 (TypE spECImEN, prObabLy HOLOTypE Of paviei var. minor ) ; HNHM 11916 (damaGEd HOLOTypE Of fractus , sEE rEmarks), BaN LaO, LEG. MEssaGEr; VIETNam, NaTUrsCHUTzpark CUC PHUONG bEIm DOrf DONG, Im REGENwaLd am FUssE vON KaLkfELsEN, LEG. T. PóCs, OCT 1963 ; SMF 158414 (HOLOTypE Of compressicosta ), CHINa, PaTUNG, HUpEI, LEG. FUCHs , COLL. BOETTGEr.

Museum material examined. MNHN IM-2012-27027/1, TONkIN, BaN LaO, COLL. STaadT, 1969; MNHN IM- 2012-27029/2, TONkIN, PaC-KHa, COLL. DENIs, 1945; MNHN IM-2012-27036/1, TONkIN, LEG. MEssaGEr; NHMUK 1910.1.21.10/1, BaN LaO, TONkIN, prObabLy LEG. MEssaGEr; NHMUK 1904.11.10.3/1, TONkIN; NHMUK 1904.8.1.7/ 1, HaUT TONkIN; NHMUK 20150485/2, THaT KHé, TONkIN, E. SykEs COLL. 1954; NHMUK 20150491/2, (LabELLEd as Alycaeus paviei ), BaU Has (INCOrrECT spELLING Of BaN LaO), E.R. SykEs COLL., ACC. 1954; SMF 346401/1 (sEE UNdEr Metalycaeus sp. aNd D. nanus ), VIETNam: TONkIN, COLL. JaECkEL; MNHN IM-2012-27213/1 (Ex MNHN IM-2012- 27035 = vanbuensis ), TONkIN, LaO Kay, COLL. LETELLIEr, 1949,.

New material examined. JUO/1, OK/1, 20100510B CHINa, HUNaN, LIfUTa ZHEN, NEar KUzHUHE, 29°19.23'N, 110°08.15'E, LEG. K. OHara, K. OkUbO & J.U. OTaNI, 10 May 2010 ; HA/3, 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 ; HA/2, 2013/4 CHINa, GUaNGxI, BOsE SHI, LEyE XIaN , MOLI CUN, CLIffs S Of THE vILLaGE ON THE LEfT sIdE Of THE BULIU RIvEr, 540 m, 24°39.436'N, 106°43.245'E, LEG. A. HUNyadI & M. SzEkErEs, 0 8 SEp 2013 ; HA/2, 2013/20 CHINa, GUaNGxI, LaIbIN SHI, XINGbIN QU, QIdONG XIaNG, CLIffs abOvE THE POLIU ELEmENTary SCHOOL, 150 m, 24°0.512'N, 109°4.288'E, LEG. A. HUNyadI & M. SzEkErEs, 20 SEp 2013 ; PGB/2 ( Ex COLL. OHara), 20 050614 A CHINa, GUaNGxI, NapO XIaN, NapO, GaNdUOyaN, 1587 m, 23°25.22979'N, 105°50.07308'E, LEG. Y. NakaHara, K. OHara, K. OkUbO & J.U. OTaNI, 14 JUNE 2005 ; HA/1, 2009/102 CHINa, GUaNGxI, BOsE SHI, NapO XIaN, NapO, GaNdUOyaN, rOCk waLL abOvE THE CavE, 460 m, 23°25.290'N, 105°50.383'E, LEG. A. HUNyadI, 20 OCT 2009 ; PGB/1 (Ex COLL. OkUbO), 20060110C CHINa, GUaNGxI, NapO XIaN, LONGHE XIaNG, GravEyard aT rIGHT sIdE Of rOad, 1153 m, 23°21.14377'N, 105°57.00734'E, LEG. K. OHara, K. OkUbO & J.U. OTaNI, 10 JaN 2006 ; OK/1, OKA /1, PGB/1 ( Ex COLL. OkUbO), 20060110G CHINa, GUaNGxI, NapO XIaN , POHE XIaNG, NaCHI, 913 m, 23°16.45981'N, 105°58.97426'E, LEG. K. OHara, K. OkUbO & J.U. OTaNI, 10 JaN 2006; HA/2, 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; PGB/1 ( Ex COLL. K. OkUbO), 20041109 A CHINa , GUaNGxI, GUIGaNG SHI, GUzHaNG XIaNG, WUsHaN XIaNG, 131 m, 23°21.178'N, 109°17.432'E, LEG. Y. NakaHara, K. OHara, K. OkUbO & J.U. OTaNI, 0 7 NOv 2004; HA/2, 2009/74a CHINa , GUaNGxI, GUIGaNG SHI , GUzHaNG XIaN, CHUaNsHaN CUN, rOad LEadING TO NOrTH, rOCks IN THE EasT, 160 m, 23°20.865'N, 109°19.169'E, LEG. A. HUNyadI, 0 9 OCT 2009; PGB/2 (Ex COLL. OHara), 20041109 E CHINa , GUaNGxI, GUIGaNG SHI , GUzHaNG XIaNG, bEyONd SHa CUN, 125 m, 23°18.180'N, 109°15.277'E, LEG. Y. NakaHara, K. OHara, K. OkUbO & J.U. OTaNI, 0 9 NOv 2004; HA/1 + 1 wEaTHErEd sHELL, 2009/96 CHINa , GUaNGxI, GUIGaNG SHI , GUzHaNG XIaN, EasTErN EdGE Of SHa CUN – LITaNGCUN, 140 m, 23°18.816'N, 109°16.211'E, LEG. A. HUNyadI, 17 OCT 2009; HA/1, 2009/95 CHINa , GUaNGxI, GUIGaNG SHI , GUzHaNG XIaN, ENvIrONmENT Of CrOssrOad Of PaN CUN , 130 m, 23°19.072'N, 109°17.320'E, LEG. A. HUNyadI, 17 OCT 2009; PGB/1 (Ex COLL. K. OkUbO), 20030318B CHINa , GUaNGxI, GUIGaNG SHI, GUzHaNG XIaNG, LIaNGGUdadUI, NO GPS daTa, LEG. K. OkUbO, 18 Mar 2003; OK/1, 2004 1107A CHINa , GUaNGxI, BINyaNG XIaN, LITaNG ZHEN, CHENTaO, 79 m, 23°12.165'N, 109°12.771'E, LEG. Y. NakaHara, K. OHara, K. OkUbO & J.U. OTaNI, 0 7 NOv 2004; OK/2, 20050324B CHINa , GUaNGxI, CHONGzUO XIaN, TaIpINGzHEN, LEG. SH. MOrIya & K. OHara, 24 Mar 2005; HE/1, Vn 09-32 VIETNam , BaC KaN PrOvINCE, Ba Bé NaTIONaL Park , DaN DaNG waTErfaLL, 168 m, 22°27.150'N, 105°34.205'E, LEG. CH . & J. HEmmEN, 19 OCT 2009; HE/1, Vn 09-33 VIETNam , BaC KaN PrOvINCE, Ba Bé NaTIONaL Park, sUrrOUNdINGs Of Na PHOONG CavE, LEG. CH . & J. HEmmEN, 20 OCT 2009; PGB/1 ( Ex COLL. OkUbO), 20070414B VIETNam , BaC KaN PrOvINCE, BabE, BabE NaTIONaL Park, Na POONG CavE, 22°23.36043'N, 105°36.77697'E, LEG. K. OkUbO, 14 Apr 2007; HE/1, Vn 10-68 VIETNam , CaO BằNG PrOvINCE, rIGHT Off OLd rd., Ca. 33 km frOm CaO BằNG TO ĐôNG KHê, 22°27.547'N, 106°22.331'E, LEG. CH . & J. HEmmEN, 26 Mar 2010; HE/3, PGB/1 ( Ex COLL. HEmmEN), Vn 09-18 VIETNam , LạNG SƠN PrOvINCE, Ca. 27 km S Of THấT KHê, rIGHT sIdE Off rd. #4 (LạNG SƠN-THấT KHê), Ca. 300 m, 22°07.484'N, 106°35.427'E, LEG. CH . & J. HEmmEN, 13 OCT 2009; DDS/7, DDS4 VIETNam, SON La PrOvINCE , MUONG La DIs. , LImEsTONE karsT IN MUONG BU COm, 718 m, 21°24'05.1"N, 104°06'13.2"E, LEG. Đ.S. Đỗ, 10 NOv 2013; HE/1, Vn 11-104 VIETNam , SƠN La PrOvINCE, rIGHT sIdE Off rOad MộC CHâU TO SƠN La, 20°52.567'N, 104°35.310'E, LEG. CH . HEmmEN, 14 OCT 2011; NHMUK 19991434 /1, VIETNam , NINH BINH PrOvINCE , CUC PHUONG NaTIONaL Park , PrEHIsT. MaN CavE, STEEp LImEsTONE sLOpE wITH dIsTUrbEd fOrEsT, HaNdpICkEd + sOIL sampLE, 20.21N, 105.54E (apprOx.), LEG. J.J. VErmEULEN & L. DEHarvENG, Ex COLL. VErmEULEN, 10 OCT 1998; WM/1 , MAA6 VIETNam 39 , NINH BINH PrOvINCE , CUC PHUONG NaTIONaL Park, 1 km WNW Of XOm BONG, 20.21°N, 105.54°E, LEG. J. VErmEULEN, 10 OCT 1998; WM/2 , MAA1 VIETNam , THaNH HOa PrOvINCE, PU LUONG NaTIONaL Park, LImEsTONE HILL NEar smaLL NaTIvE vILLaGE Am , 20°27.39'N, 105°13.65'E, LEG. W. J.M. MaassEN, 21 SEp 2003 (LOCaLITy COdE: WMVT.0344); WM/2 , MAA5 VIETNam , QUaNG NINH PrOvINCE, Ha LONG Bay arEa , DaU BE IsLaNd , 20°46.49'N, 107°07.99'E, LEG. W.J.M. MaassEN, 15 SEp 2003 (LOCaLITy COdE: WMVT.0340); WM/1, MAA7 VIETNam , QUaNG NINH PrOvINCE, Ha LONG Bay arEa , TIEN ONG CavE ON HaNG TraI IsLaNd , COLLECTEd INsIdE THE CavE, 20°48.96'N, 107°07.33'E, LEG. W.J.M. MaassEN, 0 6 SEp 2003 (LOCaLITy COdE: WMVT.0328); MNHN IM-2012-27331 /1, 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 ; MNHN IM-2012-27330/1, LaOs, Tay CHaNG (UNkNOwN LOCaLITy).

Diagnosis. A smaLL TO LarGE (UsUaLLy mEdIUm sIzEd) spECIEs wITH vEry LONG R2 HavING TypICaL Metalycaeus - TypE rIbs, a sHarp swELLING ON R3 aNd a UsUaLLy rOUNdEd apErTUrE. THE spECIEs sHOws a GrEaT varIabILITy aCrOss pOpULaTIONs IN TErms Of sIzE, sHELL sHapE aNd THE LENGTH Of R2.

Description of the holotype of heudei . SHELL ( FIGUrE 52A ) IvOry; sHELL OUTLINE sLIGHTLy OvaTE frOm dOrsaL vIEw, spIrE sLIGHTLy ELEvaTEd; EdGE Of bOdy wHOrL rOUNdEd; prOTOCONCH ELEvaTEd, CONsIsTs Of sLIGHTLy mOrE THaN 1.75 wHOrLs, fIrsT ONE aNd a HaLf wHOrLs NEarLy smOOTH, LasT HaLf wHOrLs wITH fINE spIraL LINEs; R1 CONsIsTs Of 1.5 wHOrLs, rEGULarLy rIbbEd; rIbs wIdELy-spaCEd OvEraLL, bECOmING GradUaLLy dENsEr TOwards ENd Of R1, arEa bETwEEN rIbs wITH vEry fINE spIraL sTrUCTUrE; TraNsITION bETwEEN R1 aNd R2 NOT CONspICUOUs, bECaUsE rIbs bECOmE ONLy sLIGHTLy dENsEr; R2 wITH sHarp, wIdELy-spaCEd rIbs; CrOss sECTION Of rIbs COULd NOT bE ExamINEd, bUT prObabLy sImILar TO OTHEr Metalycaeus spECIEs HavING wIdELy-spaCEd rIbs; LENGTH Of R2 aNd R3 sLIGHTLy LEss THaN a HaLf wHOrL COmbINEd, R2 sLIGHTLy LONGEr THaN R3; TraNsITION bETwEEN R2 aNd R3 CLEarLy vIsIbLE dUE TO a CONspICUOUs, dEEp CONsTrICTION; R3 wITH ELEvaTEd, sTrONG swELLING, wHICH Is fINELy, dENsELy rIbbEd; arEa bETwEEN swELLING aNd apErTUrE wITH IrrEGULar GrOwTH LINEs; apErTUrE rOUNdEd; OUTEr LIp ExpaNdEd aNd sLIGHTLy rEfLECTEd, EspECIaLLy IN dIrECTION Of UmbILICUs; INNEr LIp THICkENEd aNd sLIGHTLy prOTrUdING; dIsTaNCE bETwEEN TwO LIps rELaTIvELy LarGE.

Measurements (in mm). D = 3.6–7.2, H = 2.3–4.8 (N = 32). SEE aLsO TabLE 4.

......continued on the next page Operculum. BOTH sIdEs Of THE OpErCULUm was ExamINEd IN THE 20030318B sampLE, wHErEas ONLy THE OUTEr sIdE Has bEEN ExamINEd IN THE fOLLOwING ONEs: 20070414B, 20041107 A, 20050324B, MNHN IM-2012-27027, MNHN IM-2012-27036. THE INNEr sUrfaCE ( FIGUrEs 49C–D ) Is wITH aN ELEvaTEd NIppLE, THE OUTEr sUrfaCE Is smOOTH, aNd vEry OfTEN COvErEd by a THIN LayEr Of mUd. If IT Is CLEaN, THE OUTEr sUrfaCE Is GLOssy, smOOTH, THE mULTIspIraL sTrUCTUrE Is barELy vIsIbLE, Or NOT vIsIbLE aT aLL.

Variation in specimens. Metalycaeus heudei Is a vEry varIabLE spECIEs IN sHELL sIzE, spIrE HEIGHT, LENGTH aNd sHapE (bULGING Or NOT) Of R2 aNd THE sTrENGTH Of THE swELLING ON R3. ONE pOpULaTION (2013/16) Has aN ExTErNaLLy CrENULaTEd pErIsTOmE, wHICH Is rOUNdEd IN THE OTHErs. VarIabILITy wITHIN pOpULaTION Is LOw, aLTHOUGH mOsT avaILabLE sampLEs CONTaINEd fEw sHELLs. TabLE 4 COmpILEs THE varIabLE TraITs aNd THEIr CHaraCTEr sTaTEs IN ExamINEd pOpULaTIONs. SEE aLsO rEmarks.

Differential diagnosis. Metalycaeus muciferus LaCks THE swELLING ON R3 aNd Has mUCH sHOrTEr R2. Metalycaeus libonensis Has a sHOrTEr R2, aNd R3, aNd THE swELLING Of R3 Is sITUaTEd mUCH CLOsEr TO THE pErIsTOmE THaN IN M. heudei . MOrEOvEr, THE apErTUrE Of M. libonensis Is mOrE ObLIqUE (THE UppEr parT Of THE pErIsTOmE Is mOrE prOTrUdING aNTErIOrLy) THaN THaT Of M. heudei . SEE aLsO UNdEr M. oharai n. sp. aNd M. latecostatus .

Distribution. Alycaeus heudei Is wIdELy dIsTrIbUTEd frOm NOrTHErN VIETNam (NINH BINH PrOvINCE) aNd NOrTHErN LaOs (LUaNG PrabaNG PrOvINCE) TO THE CHINEsE YUNNaN, HUNaN aNd HUbEI prOvINCEs. MOsT pOpULaTIONs arE kNOwN frOm NOrTHErN VIETNam aNd GUaNGxI ( FIGUrE 54 ).

Remarks. THE HOLOTypE Of Chamalycaeus fractus Is damaGEd. AfTEr fINIsHING THE drawING Of THE HOLOTypE, wHICH was pUbLIsHEd IN THE OrIGINaL dEsCrIpTION, a COLLEaGUE Of ANdrás VarGa sTEppEd ON THE sHELL by aCCIdENT. As a rEsULT, THE apEx aNd apErTUraL rEGION Of THE sINGLE kNOwN sHELLs was brOkEN. THE rEmaINING apprOxImaTELy ONE wHOrL Of THE HOLOTypE Is dEpOsITEd IN THE HNHM (A. VarGa, pErs. COmm., JULy 2014). WE ExamINEd THaT sHELL fraGmENT, bUT IT dId NOT prOvIdE ENOUGH INfOrmaTION. THE drawING prEsENTEd IN THE OrIGINaL dEsCrIpTION ( FIGUrE 52E ), HOwEvEr, Is dETaILEd ENOUGH TO dECIdE THE TaxONOmIC sTaTUs Of C. fractus . MOrEOvEr, wE ExamINEd spECImENs sUbsEqUENTLy COLLECTEd aT THE samE LOCaLITy (NHMUK 19991434, FIGUrE 52D ).

WE fOUNd NO NOTabLE dIffErENCEs bETwEEN THE HOLOTypEs Of A. paviei aNd A. paviei var. minor ( FIGUrEs 51A–B ) ExCEpT fOr THE sIzE, THErEfOrE THE LaTTEr Is NOT a dIffErENT TaxON. TypICaL A. heudei ( FIGUrE 52A ) Has a LOwEr spIrE aNd a sHOrTEr R2 THaN TypICaL A. paviei . THEsE dIffErENCEs arE, HOwEvEr, NOT sTabLE aCrOss pOpULaTIONs. SOmE pOpULaTIONs sHOw INTErmEdIaTE CHaraCTEr sTaTEs bETwEEN A. heudei aNd A. paviei IN TErms Of bOTH spIrE HEIGHT aNd TUbE LENGTH, wHErEas OTHEr sHELLs arE sImILar TO ONE TaxON IN ONE CHaraCTEr, bUT TO THE OTHEr TaxON IN THE OTHEr TraIT ( TabLE 4). THE HOLOTypE Of C. compressicosta ( FIGUrE 50B ) dIffErs frOm THE HOLOTypE Of A. paviei by THE sHOrTEr aNd LEss bULGING R2 aNd a LEss ELEvaTEd spIrE. TypICaL A. heudei spECImENs dIffEr frOm THE HOLOTypE Of C. compressicosta by THE fLaTTEr sHELL aNd LOwEr swELLING ON R3. NONE Of THE dIffErENCEs bETwEEN THE HOLOTypEs Of C. compressicosta , A. heudei aNd A. paviei arE sTabLE aCrOss pOpULaTIONs, aNd THErEfOrE, sUffICIENT TO dIffErENTIaTE C. compressicosta frOm THE TwO OTHEr fOrms. THE drawING Of THE HOLOTypE Of C. fractus aNd THE spECImEN COLLECTEd IN THE samE LOCaLITy sHOw NO NOTabLE dIffErENCEs frOm TypICaL A. paviei sHELLs. As a CONsEqUENCE, A. paviei , A. paviei var. minor , C. compressicosta aNd C. fractus arE jUNIOr syNONyms Of A. heudei . THE TypE spECImENs Of Alycaeus zhuangiyucuii wErE NOT ExamINEd by Us. THE pHOTOs prEsENTEd IN THE OrIGINaL dEsCrIpTION ( FIGUrE 51D ), HOwEvEr, CLEarLy sHOw THaT A. zhuangiyucuii Is IdENTICaL wITH Alycaeus paviei , aNd THErEfOrE, syNONym Of Alycaeus heudei .

ACCOrdING TO SCHILEykO (2011) BaN LaO (TypE LOCaLITy Of Alycaeus paviei aNd A. paviei var. minor ) Is sITUaTEd IN LaOs (19°39'N, 103°19'E). HOwEvEr, THIs CITy (?) Is LOCaTEd prObabLy sOmEwHErE aLONG THE CHINEsE bOrdEr IN NOrTHErN TONkIN, bECaUsE IT Is UsUaLLy mENTIONEd as "BaN LaO, TONkIN". FUrTHErmOrE, prObabLy aLL sampLEs frOm BaN LaO OrIGINaTEd frOm COLONEL MEssaGEr, wHO, TO OUr kNOwLEdGE, dId NOT COLLECT IN LaOs, bUT was aN aCTIvE COLLECTOr aLONG THE NOrTHErN bOrdEr Of TONkIN. THErEfOrE, "BaN LaO" sENsU SCHILEykO (2011) Is NOT INdICaTEd ON OUr map.

Figures

FIGURE 49. Opercula of Metalycaeus species. A – B. Metalycaeus (?) awalycaeoides Páll-Gergely & Hunyadi, n. sp. (outer side, holotype, HNHM 99730). C – D. Metalycaeus heudei (Bavay & Dautzenberg, 1900) (inner side), 20030318 B, coll. OK. All images: B. Páll-Gergely.

FIGURE 50. Shells of Metalycaeus heudei (Bavay & Dautzenberg, 1900). A. 2013 / 16, coll. HA. B. Holotype (SMF 158414) of Chamalycaeus (Dicharax) compressicosta Zilch, 1957. C. 20100510 B, coll. OK. Scale represents 5 mm. All images: B. Páll-Gergely.

FIGURE 51. Shells of Metalycaeus heudei (Bavay & Dautzenberg, 1900). A. holotype (MNHN IM- 2012 - 27163) of Alycaeus paviei Bavay & Dautzenberg, 1912. B. Holotype (MNHN IM- 2012 - 27164) of Alycaeus paviei var. minor Bavay & Dautzenberg, 1912. C. 2013 / 4, coll. HA. D. holotype of Alycaeus zhuangiyucuii. Scale represents 5 mm. All photos: B. Páll- Gergely, except for Fig. D. (photos from the original description, with permission form He Ying; note that the photos were taken using green background).

FIGURE 52. Shells of Metalycaeus heudei (Bavay & Dautzenberg, 1900). A. holotype. B. MAA 5. C. Vn 09 - 32, coll. Hemmen. D. NHMUK 19991434. E. drawings of the holotype (HNHM 11916) of Chamalycaeus (Dicharax) fractus Varga, 1974. Scale represents 5 mm. Photos: B. Páll-Gergely (A – C) and H. Taylor (D).

FIGURE 53. Protoconchs of Metalycaeus species. A – B. Metalycaeus (?) okuboi Páll-Gergely & Hunyadi, n. sp. (holotype, HNHM 99713). C – D. Metalycaeus heudei (Bavay & Dautzenberg, 1900), 20030318 B. All images: B. Páll-Gergely.

FIGURE 54. Distribution of Metalycaeus heudei (Bavay & Dautzenberg, 1900). Empty circles indicate figured populations. 1. Badong (type locality of Chamalycaeus compressicosta Zilch, 1957). 2. 20100510 B. 3. 2013 / 16. 4. 2013 / 4. 5. Mengzi (type locality of Alycaeus zhuangiyucuii Yang, Fan, Qiao & He, 2012). 6. Vn 09 - 32. 7. Cuc Phuong National Park (type locality of Chamalycaeus fractus Varga, 1974). 8. MAA 5.