Jan Mayen Mollusca. 225 



ture : strong prominent longitudinal ribs , that on the last whorl 

 appear sometimes indistinct, sometimes forming a row of pro- 

 truding knots along the ridge, and coarse spiral ribs, the number 

 of which vary from 5 to 8 on the last whorl ; on those above 

 they are indistinct. Mouth round oval, ^17 of the whole length, 

 somewhat expanded below and forming behind an angle with the 

 almost straight colummelle; no umbilicus, but a more or less 

 deep split. The size L. 5 ra. m. B. 2m.m. 



Operculum (Fig. 4 a) ovalshaped, with a rather large lateral 

 spire, moreover but slightly striated. 



Radida, Fig. 4h, 

 The shell has as a rule a coating of brown cruste, that 

 often covers the upper whorls in a thick layer. 



Var. alba: white of color. 

 One specimen of the many found was nearly white. Hab. 

 St. 233—70 fath. St, 224—95 fath and St. 225-300 fath. 



Dr. Jeffreys informs me that this species has been found by 

 Torell on one of the Swedish expeditions to Spitzbergen. 



Its nearest ally is B. scrobirulata Møll., but this latter is 

 distinguished by its smaller size, the always white color, a rounder 

 mouth, and the sculpture consists of more numerous, and less 

 prominent longitudinal ribs, which extend farther down on the 

 last whorl, forming with the spiral ribs a regular cancellation. 



CeritJmm costulata Moll. St. 237—263 fath. 



Trichitropis conicaMöW. St. 237-263 fath. 



Cancellaria viridula Fab. St. 224—95 fath. 



Natica afinis GmL St. 224-95 fath. and St. 225-300 fath. 



Natica (Lunatia) pallida Br. & Sowb. („Beechey's Voyage" PI. 

 34, Fig. 15). St. 223-70 fath. St. 224—95 fath. and St. 225 

 -300 fath. 



This appears to be a good species that is easily distinguished 

 from N. groerdandica Moll, by the comparatively greather length 

 of its shell and by the more elongated shape of the mouth. 



Cyllelma solitär ia Say, in sculpta Totten. 

 10 to 15 fath. 



Cylichna striata Br.; occtdata Migh, & Ad.; BeinJiardll Moll.; 

 propingna Sars. 



St. 223-70 fath. St. 224-95 fath. 



Utricidus glohosus Lov. 

 One specimen St. 237-263 fath. 



