46 



Gasteropoda Opisthobranchiata. 



Depth. 



20 to 24 f. 



Living at 



Frequency, &c. 



20 to 24 f. sand&m. | extremelj abundant 



Ditui-pa subiilata 



Being — 



Acephala lameUibranchiata 54 



Acepliala palliobranchiata 1 



Pteropoda 5 J-1 50 Species. 



Gasteropoda prosobranchiata 'JO 



Gasteropoda opisthobrancliiata ..... 6 



Of these all that are recorded as North American species are Soxicaca 

 arclica, Janthina communis, Lamellaria perspicua. 



