312 TROCHID^. 



spire and deep sutures ; whorls angulated at the periphery, where 

 they are sulcated. 4 sp. Red Sea. T.fanulum, G-mel. (Ixxxi, 81). 



LEPTOTHYRA, Carp. (Leptonyx, Carp, and Ads. Homalopoma, 

 Carp.) Shell small, turbinated, thick, not umbilicated ; aperture 

 circular, slightly angulated anteriorly. The type of this group 

 is the California shell identified as conspecific with the Mediter- 

 ranean species Turbo sanguineus, Linn. ; the latter, however, 

 has a calcareous operculum, and is therefore a true TtirhO, whilst 

 the operculum of this is corneous, multispiral. 



CALLiOTROCHUS, Fisclier. TJncharacterized. T. phasianellus, 

 Desh. 



zrzYPHiNUS, Gray. (Calliostoma, Swains. Conulus, Nardo.) 

 Shell trochiform, conical, not umbilicated; last whorl angulated 

 and usually ribbed at the periphery ; aperture quadrangular ; 

 columella simple, oblique, often ending in a tooth in front. 28 

 sp. Universally distributed. T. zizyphinus, Linn. (Ixxxi, 

 48, 49). 



EUTROCHUS, Ad. Zizyphinus-like shells, but umbilicated, the 

 umbilicus encircled by a carina. 3 sp. West Indies, Indian 

 Ocean, Australia. T. {EutrochusJ jujubinus, Linn. (Ixxxi, 82). 



TURCICA, H. and A.Adams. Shell conoidal, thin, subdiaphanous, 

 imperforate, ornamented with revolving granulated ribs ; suban- 

 gulated at the periphery ; suture channeled ; columella tortuous, 

 pointed in front, in the middle spreading into a lamina, with one 

 or two teeth on its edge. T. moniliferus, Ads. (Ixxxi, 51 '. 



TROCHODON, Sccley, 1861. Resembling Zizyphinus, thin, 

 having on the columella two prominent teeth, = Turcica (?). T. 

 cancellatus. Cambridge Greensand. 



PTYCHOSTYLUS, Gabb. According to the characteristics given 

 by Gabb, apparentl}^ does not differ essentially from Turcica. 

 The columella is solid, with two oblique folds, P. caffea, from 

 California, is quoted as the type. 



LISCHKETA, Fischei'. Uncharacterized. T. moniliferus, Lam. 

 Japan. 



ODONTOTROCHUS, Fischcr. Uncharacterized. T. chlorostomus, 

 Menke. Australia. 



THALOTiA, Gray. Shell ovate-turriculated, rather thick, not 

 umbilicated"; whorls flattened, with revolving ribs, Avhich are 

 sometimes granulated ; aperture subrotund ; columella tuber- 

 culate, truncate in front; outer lip rather thick, crenulated 

 within. 8 sp. Australia, Indian Ocean. T. conicus, Gray 

 (Ixxxi, 52). 



ELENCHUS, Humphrey. Shell elevated conoidal, not umbili- 

 cated, spire sharp; whorls rather flat, smooth, polished, usually 

 with distant revolving incised lines ; aperture suboval ; colu- 

 mella with a tooth-like projection in the middle ; outer lip 

 thickened within. 6 sp. Australia. Brilliantly colored shells, 



