Metalycaeus (?) libonensis (Chen, Li & Luo 2003)

Chamalycaeus libonensis Chen, Li & Luo, 2003: 619 –620, figs 1–3.

Type locality. " FENG DONG, LIbO COUNTy (25° 4'N, 107°8'E), GUIzHOU PrOvINCE, CHINa ".

Diagnosis. A LarGE spECIEs wITH LONG R2, sHOrT R3, dEEp CONsTrICTION aNd CONspICUOUs swELLING ON R3, vEry CLOsE TO THE pErIsTOmE.

Original description. "SHELL smaLL, sLIGHTLy THICk, sUbdEprEssEd, sEmITraNsparENT, CONE. WHOrLs 3½-4½, mOdEraTELy CONvEx, spIrE HIGH, HIGH-CONOId, aNd THE prOTOCONCH aNd sECONd GENEraLLy smOOTH, sUTUrE dEEp. SHELLs yELLOwIsH brOwN, sUrfaCE wITH vEry fINELy aNd sOmEwHaT dIsTINCT dENsE ObLIqUELy COarsELy rIb sTrIaTEd, aNd wITH 2.25 mm prOjECTION as wOrm-fOrmEd aT THE sUTUrE Of THE bOdy wHOrL. ApErTUrE ELLIpTICaL, wITH a NECk, aNd wITH sEmI-aNNULar swELLING ON THE NECk. OpErCULUm CIrCULar, sINk, INNEr sUrfaCE Has a papULE-fOrmEd prOjECTION. UmbILICUs wIdE, dEEp, CavE-sHapEd, dIam. Of UmbILICUs 2.15 mm, raTIO Of UmbILICUs dIamETEr TO sHELL dIamETEr 0.26."

Measurements (in mm). D = 5.9–6.6, H = 4–5 (aCCOrdING TO THE OrIGINaL dEsCrIpTION).

Differential diagnosis. SEE UNdEr M. heudei.

Remarks. WE HavE NOT ExamINEd spECImENs Of M. libonensis; THE dIaGNOsIs aNd THE dIffErENTIaL dIaGNOsIs arE basEd ON THE OrIGINaL dEsCrIpTION. THIs spECIEs Is TENTaTIvELy CLassIfIEd IN Metalycaeus bECaUsE ITs sImILarITy wITH M. heudei, aLTHOUGH THE OrIGINaL dEsCrIpTION dId NOT mENTION spIraL sTrIaTION ON THE prOTOCONCH.