Oi\OBA. 381 



El. A. abyssicola, Forbes, pi. 35, fig. 3. Shell, A. ca- 

 lathiscus, Montagu, fig. 3, a. 



In this genus the shells are turbinate, with rounded 

 apertures and cancellated whorls, and there is a conspi- 

 cuous varix on the outer lip; the species appear chiefly to 

 abound along the shores of temperate countries. 



Species of Alvania. 



abyssicola, Forbes. fulva, Mich. 



Beanii, Hanley. Gougeti, Mich. 



calathiscus, Mont. grossa, Mich. 



cancellata, Lam. marginata, Mich. 



cimex, Linn. Montagui, Payr. 



costulata, Risso. sculpta, Fhil. 



crenulata, Mich. striatula, Linn. 



Europsea, Risso. trochlea, Mich. 



fenestrata, Krauss. Zetlanclica, Mont. 



Genus ONOBA, H. and A. Adams. 



Operculum ovate, simple, subspiral. 



Shell elongated, whorls numerous, rounded, spirally 

 striated ; aperture oval, entire in front, peritreme conti- 

 nuous, thickened, straight or slightly everted. 



S(/n. Turbonilla, Leach, not Risso. 



Ex. O. striata, Montagu, pi. 35, fig. 4. 



This genus includes a small group of elegantly- 

 formed shells, more or less partaking of the characters 

 of Rissoa, but their whorls are not longitudinally ribbed, 

 and the peritreme is not dilated. 



