APORRIIAIS. 281 



Shell with the canal bent to the right ; outer lip si- 

 nuous, lobed, or digitate. 



The rostriform head, sessile eyes, and rudimentary 

 siphon, together with certain peculiarities of the shells, 

 especially obvious in some fossil forms, indicate strong 

 affinities with Cerithium, which has induced Professor E. 

 Forbes to include both Cerithium and Aporrhais in the 

 same family; the simple foot and position of the eye& 

 serve to distinguish these animals from those of Strom- 

 hidcE. 



Genus APORRHAIS, Aldrovandus. 



Mantle-margin expanded, lobed, or digitate. 



Operculum ovate, with subconcentric lamellae. 



Shell fusiform; aperture narrow, ending anteriorly in 

 a canal or groove; outer lip dilated with age, expanded, 

 angulately lobed, or thickened. 



Sijn. Tritonidium, Mull. Chenopus, Phil. 



Ex. A. pes-pelicani, LinncBus, pi. 26, fig. 5. Oper- 

 culum, A. pes-pelicani, fig. 5, «, 5, b. Shell, A. pes-peli- 

 cani, fig. 5, c. 



There are three species of this genus found on our 

 coasts, and in the Mediterranean, and another is from 

 North America, principally from the banks of Newfound- 

 land. 



Species of Aporrhais. 



occidentalis, Beclc. pes-pelicani, Linn. 



pes-carbonis, Brorju. Serresiauus, Mich. 



VOL. r. GO 



