OMPHALIUS. 429 



ulivaceum, Anton. rusticum, Gmel. 



PfeifFeri, Phil. tridentaturo, Pot. and Mich. 



puUigo, Martyn. tropidophorum, A. Adams. 

 rugosum, A. Adams. 



Genus OMPHALIUS, Philippi. 



Shell turbinate, axis perforated ; whorls with transverse 

 series of granules, the last rounded at the periphery ; um- 

 bilicus surrounded by a ring-like callus ending at the fore 

 part of the inner lip in a tooth, often with several tubercles 

 beyond it. 



Ex. O. viridulus, Gmelin, pi. 49, fig. 2. Operculum, 

 O. viridulus, fig. 2, a. 



Omphalitis, unlike Polydonia, is truly umbilicated, and 

 the last whorl is rounded ; the granular nature of the whorls 

 will distinguish it from Chlorostoma, and the spiral callus 

 round the umbilicus, and the whorls not being tumid, will 

 separate it from Gibbula ; the outer lip, moreover, is 

 usually grooved internally. 



Species of Omphalius. 



Brazilianus, Mke. maculo-striatus, C.B.Adams. 



Californicus, A. Adams. melaleucos, Jonas. 



canus, Koch. modestus, Koch. 



carueus, Gmel. nodicinctus, A. Adams. 



cruciatus, Chem. quadricarinatus, Gmel. 



excavatus, Lam. quadricostatus, Wood. 



fasciatus, Born. scalaris, Anton. 



fuscescetis, Phil. scabriculus, V. d. Busch. 



granifer, A. Adams. semigranosus, A. Adams. 



Gruneri, Phil. sordidus, Phil. 



Hottesserianus, VOrb. siicticiis, A. Adams. 



liratus, A. Adams. viridulus, Gmel. 



