178 VERMETUS. 



Y. SPIRORBIS, Sowb. PI. 51, fig. 50. 



Planorbiform, white, smoothish, whorls not in contact. 



? Cape of Good Hope. 

 Y. ANNULATUS, D.audin. PI. 51, figs. 51, 52. 



Irregularly spiral, transversely lamellate. 



West Indies, on Shells. 



Yar. CORRODENS, d'Orb. (fig. 51). Having a peripheral carination, 

 forming a tooth-like projection at the mouth. This is var. 

 dentifera of Morch. 



Yar. IRREGULARIS, d'Orb. (fig. 52). Brownish black, irregularly 

 contorted, transversely rugosely plicate. This is var. glome- 

 rata, Morch. 



Yar. TROCHICOLA, Morch (unfigured). 



Y. GLOMERATUS, Bivona. PI. 51, fig. 53 ; PI. 52, figs. 55-58. 



Conglomerated, tubes cylindrical or subangulated, contorted, 

 transversely undulately rugose. Mediterranean Sea. 



Morch has vars. CRUSTANS and TUBULOSA = ANNULATA, Lam. 

 (fig. 58). 



V. cristatus, Biondi, is the young of this species. Yaillant 

 remarks that Daudin's species is smaller than V. annulatus, Lam., 

 and corrodes the surface upon which it is attached ; as Daudin has 

 priority he proposes for the Lamarckian species V. annularium. 



Monterosato has substituted the name petrzea, because of Ser- 

 pula glomerata, Linn.; he adds a var. minor. 



Embryonal whorls smooth, projecting in the centre of the shell, 

 and not unlike a very small Amnicola. Has more regular whorls 

 and wants the tooth-like process of the carina in the aperture of 

 V. annulatus. 



Doubtful and Unfgured Species. 



SERPULA COSTALTS and S. iNFUNDiBULUM,of Chenu's Illust. Conch. 

 Y. ALBIDUS, Carp. Mazatlan. 



Y. STRAMONIT^E. Morch. ? Guinea. 



Y. ANGULIFERA, Monts. Tripoli. 



Y. PLANORBIS, Dkr. PI. 52, fig. 51). 



Piano rbiform, somewhat solid, white, carinated, transversely 

 sublamellate, whorls in contact. 



Japan, slightly immersed in the surface of 



Vermetus imbricatus, Dkr. 



