PLEUROTOMID^. 183 



Shell fusiform or tnrriculated, oblong-oval, smooth ; aperture 

 oval-elongated, large, produced into a twisted canal in front ; 

 columella carinated, anteriorly twisted, with a small basal 

 plication. 



Family PLEUEOTOMID^. 



Shell fusiform, canaliculated, outer margin of aperture with a 

 slit near the suture. Operculum corneous, annular, not always 

 present. Animal with tentacles wide apart, the eyes at their 

 outer bases. 



Pleurotoma, Lam. 



Etym. — Pleura^ the side, and toma, a notch. 



Syn. — Turris, Humph. Cochlespira, Conrad. Gemmula,Weink, 

 Eucheilodon, Gabb. 



Distr. — Over 500 sp. World-wide ; low-water to 100 fms. 

 Fossil, nearly as many. Cret. — . F. babylonia^ Lam. (Ivii, 13). 



Shell tnrriculated, fusiform, terminated anteriorly b}^ a straight, 

 more or lesg long canal; aperture oval, columellar lip smooth, 

 straight or sinuous ; outer lip somewhat sinuous, with a posterior 

 sinus. 



SURCULA, H. and A. Adams. Tnrriculated, internal lip obsolete ; 

 canal long, narrow, slightly twisted. F. nodifera, Lam. (Ivii, 14). 



SURCULITES, Conrad. Shell with spire and body-volution nearly 

 equal ; the latter obconical, rectangular near the top, and flattened 

 or concave above from the angle to the suture ; sinus of lip above 

 the angle of the whorls, shallow and broad. S. annosa, Conrad. 

 Mr. Conrad never characterized it ; but his type-species has the 

 characters given above. It seems to be very near to Surcula but 

 may probably be retained for a group of Tertiary species, with 

 obconic body-volutions, usually referred to Pleurotoma, and 

 forming a kind of transition toward the Conidae (Meek). 



GENOTA, H. and A. Adams. (Pseudotoma, Bellardi. Crypto- 

 conus, Koen. Dolichotoma, Bellardi. Roualtia, Bell.?) Shell 

 mitriform ; whorls finely cancellated ; aperture elongated, canal 

 short; sinus profound. F. Mitrseformis, Kiener (Ivii, 15). 



BRACHYTOMA, Swaius. Shell strombiform ; columellar lip rather 

 thick ; outer lip ascending and forming a sinus or narrow canal 

 near the suture. P. Stromboides, Sowb. (Ivii, 16). 



CONOPLEURA, Hinds. Shell coniform ; aperture narrow, sinuous ; 

 columellar lip callous ; canal ver^^ short ; outer lip sinuous, with 

 a profound lateral sinus. F. striata. Hinds (Ivii, 17). 



DRILLIA, Gray. (Moniliopsis, Conrad.) Tnrriculated ; aper- 

 ture oval, oblique ; canal short, twisted ; columellar lip strongly 

 callous above. Animal with approximate tentacles and eyes at 

 their extremity. F. gibbosa^ Kiener (Ivii, 18). 



CRASSispiRA, Swains. Shell somewhat claviform,tuberculated ; 



