MOLLUSCA. 803 
Sp. Melania buccinoidea Ouiv., Buccinum prerosum L., Outv., Voyage, Pl. 
17, fig. 8, Reeve Conchyl. Syst. u. Tab. 195, fig. 2, &e. Comp. on the 
species of this sub-genus F&russac Monogr. des especes vivantes et fossiles 
_ dw genre Mélanopside, Mém. de la Soc. d’ Hist. nat. de Paris, 1. 1823, pp. 
132—164, Pl. 7, 8. 
Phalanx HII. Cerycoidea (Buccinoidea Cuv.). Cochlea spiral, 
with aperture emarginate or canaliculate towards the columella, a 
canal receiving the tube of mantle. 
Cerithium ADANS., BruG., LAM. Shell turrite. Aperture 
oval, oblique, terminated by a short canal truncated or recurved. 
Animal with two tentacles acuminate, furnished with an oculiferous 
tubercle towards the base. 
Sp. Cerithium palustre La., Strombus palustris L., Rumpx. Amb. Rariteith. 
Tab. 30, fig. @; Buatnv. Malacol. Pl. 20, fig. 4;—Cerith. telescopium, 
Trochus telescopium L., Rumen. Amb. Rariteitk. Tab. 21, fig. 12, D’ARGENV. 
Conchyl. Tab. 11, fig. 2, Buatnv. Malac. Pl. 32 bis, fig. 2, &c. A very 
numerous genus of which the species live in great part in the sea, partly 
in brackish water or at the mouths of rivers. The fossil species which are 
still more numerous (more than 300 according to DESHAYES), are almost 
all limited to the tertiary formations. Amongst these Cerithium giganteum 
deserves to be noticed, a species found in France near Grignon. 
The sub-genus Potamides (Ann. du Mus. xv. pp. 367-370) is usually 
not accepted by later writers. 
Fastigiella REEVE. 
Sp. Fastig. carinata Rerve, Ann. of Nat. Hist., second series, i. 1848, p. 66. 
(Habitus of Turritella, characters almost of Cerithium.) 
Pleurotoma Lam. Aperture produced into an elongated straight 
canal. Shell turrite or fusiform. Columella smooth. Lip cloven 
or emarginate by a sinus. ‘Two conical tentacles; eyes at the base 
of tentacles externally. Operculum horny. 
Sp. Plewrotoma babylonia Lam., Murex babylonius L., Rumpx. Amb. Rari- 
teitk. Tab. 29, fig. L, Buarnv. Malacol. Pl. 15, fig. 3, Cuv. R. Ani., éd. ill., 
Moll, Pl. 60, fig. 2, &. A numerous genus, of which also several fossil 
species are known. 
Fusus Bru. (in part), Lam. Shell destitute of spines; aper- 
ture produced into a long straight canal. Columella smooth. 
Labrum entire. Operculum horny. 
Fusus Lam. Shell fusiform, spire elongate, ventricose in the 
middle. 
