Metalycaeus muciferus ( Heude, 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 : 88-91

Metalycaeus muciferus ( Heude, 1885)

FIGUrEs 58 –59, 60, 61.

Alycoeus muciferus Heude, 1885: 96 , pl. 24, figs 1, 1a.

Alycaeus (Orthalycaeus) muciferus — Möllendorff, 1886: 171. Alycaeus helicodes Gredler, 1887: 365 , new synonym.

Alycaeus (Chamalycaeus) helicodes — Kobelt & Möllendorff, 1897: 148. Alycaeus (Chamalycaeus) muciferus — Kobelt & Möllendorff, 1897: 149. Alycaeus (Chamalycaeus) helicodes — Kobelt, 1902: 356.

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

Chamalycaeus dolichodirus (sic!)— Yen, 1939: 30, pl. 2, fig. 37. Chamalycaeus (Chamalycaeus) dolichodirus (sic!)— Zilch, 1957: 142. Chamalycaeus helicodes — Zilch, 1974: 193, pl. 7, fig. 4.

Types examined. 7 syNTypEs (MCZ 167230) Of A. muciferus CHINa, 2 paraLECTOTypEs (SMF 192225) Of A. helicodes , TCHEN-k'EOU, CHINa, PE-sHaNG, HUNaN, LEG. FUCHs, COLL. GrEdLEr. ACCOrdING TO JOHNsON (1973) paraTypEs Of muciferus arE aLsO prEsENT IN THE NMNH (INv. NUmbEr: 472340). THEsE wErE NOT ExamINEd by Us. SEE aLsO REmarks.

Museum material examined. C SMF 39254/1 (fIGUrEd IN YEN 1939, pL. 2, fIG. 37, as " Chamalycaeus dolichodirus "), HaNG-yaNG, HUpEI, CHINa, LEG. FULTON, 1894, COLL. O. BOETTGEr; SMF 346399/1 (mIxEd sampLE wITH D. cristatus : SMF 39250), PaTUNG, HUpEI, CHINa, COLL. MöLLENdOrff; NHMUK 20150487/2 (TypICaL helicodes , LabELLEd as dolichodirus ), CHaNGyaNG, E.R. SykEs COLL.

New material examined. 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/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/2, 2016/113 CHINa, CHONGqING, CHENGkOU XIaN, LONGTIaN XIaNG, NOrTHErN EdGE Of YOUfaNG, 32°01.205'N, 108°39.924'E, LEG. A. HUNyadI, 13 JUNE 2016 ; HA/4, 2015/48 CHINa, SICHUaN, CHENGdU SHI, DUjIaNGyaN SHI, QINGCHENGHOUsHaN, UNdEr BaIzHaNG BrIdGE, 1220 m, 30°56.088'N, 103°28.818'E, LEG. A. HUNyadI & M. SzEkErEs, 0 5 JUNE 2015 , HNHM 99729 /1 (fIGUrEd sHELL); 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/1, OK/1, 20090306A CHINa, GUIzHOU, HUaNGpING XIaN, FEIyUNdaxIaGU, 803 m, 26°55.116'N, 108°01.787'E, LEG. K. OHara, K. OkUbO & J.U. OTaNI, 0 6 Mar 2009 ; HA/2, 2011/15 CHINa, YUNNaN, WENsHaN ZHUaNGzU MIaOzU ZIzHIzHOU, XICHOU XIaN, XINGjIE ZHEN, DadONG 3 km TOwards BaTaNG, LaOLONG, 1195 m, 23°16.067'N, 104°32.215'E, LEG. A. HUNyadI, 22 Mar 2011 ; OK/2, 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/8, 3 jUvENILE/brOkEN sHELLs , HNHM 99711 /1, 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 ; PGB/1 ( Ex COLL. K. OkUbO), 20060110E CHINa, GUaNGxI, NapO XIaN, LONGHE XIaNG, INNEr LONGHE, 990 m, 23°22.91642'N, 105°59.98975'E, LEG. K. OHara, K. OkUbO & J.U. OTaNI, 10 JaN 2006 ; HE/1, Vn 11-141 VIETNam, Hà GIaNG PrOvINCE, km 105.5 ON rOad 4C, bETwEEN YêN MINH aNd ĐồNG VăN (NE Of Hà GIaNG TOwN), 23°08.996'N, 105°10.332'E, LEG . CH. HEmmEN, 21 Mar 2011 ; JUO/4, PGB/1 ( Ex COLL. J.U. OTaNI), 20081113 B VIETNam, Ha GIaNG PrOvINCE, VI XUGEN DIsTrICT , HUNG Ba COmmUNE, Nam PIa VILLaGE, 216 m, 22°52.064'N, 105°04.184'E, LEG. K. OHara & J.U. OTaNI, 13 NOv 2008 .

Diagnosis. A smaLL TO mEdIUm sIzEd spECIEs wITH vEry sHOrT R2 aNd R3, R2 HavING TypICaL Metalycaeus - TypE rIbs aNd R3 LaCkING swELLING.

Description of typical muciferus . SHELL ( FIGUrE 58A ) wHITE; sHELL OUTLINE sLIGHTLy OvaL frOm dOrsaL vIEw, spIrE sLIGHTLy ELEvaTEd, EdGE Of bOdy wHOrL rOUNdEd; prOTOCONCH ( FIGUrEs 61C–D ) CONspICUOUsLy ELEvaTEd frOm dOrsaL sUrfaCE, CONsIsTING Of 1.75 wHOrLs (N = 2), raTHEr maTTE, ITs ENd wITH INCONspICUOUs spIraL sTrIaTIONs; R1 CONsIsTs Of 1.5–1.75 wHOrLs, wITH IrrEGULar, wIdELy-spaCEd rIbs aNd fINE spIraL sCULpTUrE; rIbs sLIGHTLy bECOmING mOrE wIdELyspaCEd TOwards ENd Of R1; TraNsITION bETwEEN R1 aNd R2 NOT CONspICUOUs; R2 wITH dENsE, sHarp, ELEvaTEd rIbs ( FIGUrEs 60E–F ); CrOss sECTION Of rIbs Of TypICaL muciferus COULd NOT bE ExamINEd (bUT sEE rEmarks); LENGTH Of R2 aNd R3 vEry sLIGHTLy mOrE THaN a qUarTEr wHOrL COmbINEd (apprOxImaTELy 100 dEGrEEs); R2 LONGEr THaN R3; TraNsITION bETwEEN R2 aNd R3 raTHEr smOOTH, NO CONsTrICTION vIsIbLE; R3 wITH fEw wIdELy-spaCEd wrINkLEs, apErTUrE aLmOsT ExaCTLy rOUNdEd; OUTEr LIp vEry HIGH aNd sHarp, sIGNIfICaNTLy ExpaNdEd aNd sLIGHTLy rEfLECTEd; INNEr LIp sLIGHTLy THICkENEd, NOT CONspICUOUs; bOUNdary bETwEEN TwO LIps HardLy vIsIbLE.

Measurements (in mm). D = 3.3–5.3, H = 2.1–3.4 (N = 18, spECImENs frOm dIffErENT LOCaLITIEs). SEE aLsO TabLE 5.

Operculum. THE OUTEr sUrfaCE Of THE OpErCULUm Of THE TypE sErIEs Of muciferus aNd helicodes wErE COvErEd by mUd. UNdEr THE mUd, HOwEvEr, aN ELEvaTEd, mULTIspIraL, wrINkLEd LamELLa was vIsIbLE. BOTH sIdEs Of THE OpErCULUm Of sampLE 20081113 B wErE ExamINEd. THE OUTEr sUrfaCE sHOwEd mULTIspIraL CHaraCTEr wITHOUT ELEvaTEd LamELLa; THE INNEr sIdE Had a vEry smaLL, LOw CENTraL NIppLE sITTING ON THE TOp Of a GradUaLLy ELEvaTEd "HILL".

Variation in specimens. Metalycaeus muciferus Is a vEry varIabLE spECIEs IN sHELL sIzE, sHELL sCULpTUrE aNd COLOUr. TabLE 5 COmpILEs THE varIabLE TraITs aNd THEIr CHaraCTEr sTaTEs IN ExamINEd pOpULaTIONs.

Differential diagnosis. Metalycaeus muciferus CaN bE dIsTINGUIsHEd frOm OTHEr Metalycaeus spECIEs ON THE basIs Of THE sHOrT R2, aNd THE aLsO sHOrT R3, wHICH LaCks a swELLING IN ITs mIddLE. SEE UNdEr Dicharax bison n. sp., Metalycaeus heudei , M. laosensis n. sp., M. oharai n. sp. aNd M. latecostatus .

Distribution. SHELLs assIGNEd TO THIs spECIEs wErE COLLECTEd frOm mULTIpLE CHINEsE prOvINCEs (YUNNaN, GUaNGxI, HUNaN, HUbEI, SICHUaN, CHONGqING, GUIzHOU) aNd NOrTHErN VIETNam ( FIGUrE 57 ).

Remarks. TypICaL Metalycaeus muciferus ( FIGUrE 58A ) aNd M. helicodes (FIGUrE 59B) spECImENs aGrEE IN THE fOLLOwING TraITs: bOTH R2 aNd R3 arE vEry sHOrT; THErE Is NO rECOGNIsabLE CONsTrICTION aT THE bOrdEr Of THE TwO rEGIONs; THE rIbs ON R2 arE wIdELy-spaCEd aNd sHarp; pErIsTOmE rELaTIvELy THIN (aLTHOUGH sOmETImEs ExpaNdEd). WE ExamINEd a NUmbEr Of NEwLy COLLECTEd CHINEsE sampLEs, wHICH aGrEE wITH M. muciferus aNd M. helicodes IN THE abOvE mENTIONEd TraITs, aLTHOUGH sHOw dIffErENCEs IN TErms Of spIrE HEIGHT, sCULpTUrE Of R1 aNd sIzE (sEE TabLE 5 aNd FIGUrEs 58 –59). NEarLy EvEry sINGLE pOpULaTION wE ExamINEd Has CHaraCTErIsTIC fEaTUrEs, wHICH aLLOws dIsTINGUIsHING IT frOm OTHErs. THEsE dIffErENCEs arE raTHEr mINOr. MOrEOvEr, THEsE sampLEs arE smaLL aNd maINLy CONTaIN wEaTHErEd sHELLs wITHOUT OpErCULa. THErEfOrE wE dO NOT fINd IT rEasONabLE TO dEsCrIbE THEm fOrmaLLy. INsTEad, UNTIL mOrE maTErIaL bECOmEs avaILabLE, wE LIsT aLL THEsE sampLEs aNd HaNdLE THEm UNdEr a sINGLE NamE ( Metalycaeus muciferus ).

AdOLf ZILCH brOUGHT TwO spECImENs frOm GrEdLEr's COLLECTION (BOzEN = BOLzaNO) TO THE SENCkENbErG MUsEUm. HE mENTIONEd THaT THE LECTOTypE rEmaINEd IN BOLzaNO ( ZILCH 1974), THErEfOrE THE spECImENs IN THE SENCkENbErG MUsEUm arE paraLECTOTypEs (FIGUrE 59B).

THE CrOss sECTION Of R2 was ExamINEd IN ONE spECImEN Of THE pOpULaTION 2015/48 ( FIGUrE 61D ). ANTErIOr pLaTE raTHEr sTraIGHT, HOLLOw, IT Has a LOw, bUT sHarp rIb; pOsTErIOr CrUsT sTrONG, ONLy sLIGHTLy LOwEr THaN THE aNTErIOr ONE; THE mICrOTUNNEL Has a TEardrOp-sHapEd CrOss sECTION, ITs dIamETEr Is CONspICUOUsLy LarGE IN rELaTION TO THE sIzE Of THE CrUsTs. THE aNTErIOr CrUsT Of TypICaL muciferus sHELLs Is HOLLOw. SEE aLsO rEmarks UNdEr Alycaeus dolichodeiros .

Figures

FIGURE 57. Distribution of Metalycaeus species. Empty diamond. Metalycaeus zayuensis (Zhang, Chen & Zhou, 2008). Filled triangle. Metalycaeus oharai Páll-Gergely & Hunyadi n. sp. Filled square. Metalycaeus (?) awalycaeoides Páll- Gergely & Hunyadi, n. sp. Circles. Metalycaeus muciferus (Heude, 1885). Empty triangle, top down. Metalycaeus laosensis n. sp. Empty circles indicate figured populations of Metalycaeus muciferus. 1. Tchen K’eou (Chengkou), the type locality of Alycaeus muciferus Heude, 1885. 2. Changyang (SMF 39254). 3. 2015 / 48. 4. 20070714 B. 5. Pe-shang (type locality of Alycaeus helicodes Gredler, 1887). 6. 2013 / 7. 7. 2011 / 15.

FIGURE 58. Shells of Metalycaeus muciferus (Heude, 1885). A. syntype. B. 20070714 B, coll. PGB. C. 2011 / 15, coll. HA. D. 2015 / 48, coll. HA. Note that the black " operculum " of Fig. D is the posterior end of a predator fly larva. Scale represents 5 mm. All photos: B. Páll-Gergely.

FIGURE 60. R 2 ribs of Metalycaeus muciferus (Heude, 1885). A – D. 2015 / 48. E – F. MCZ 167230. Arrows show the edge of the overfolding anterior crust. All images: B. Páll-Gergely.

FIGURE 61. Protoconchs of Metalycaeus muciferus (Heude, 1885). A – B. 2013 / 7. C – D. syntype (MCZ 167230).