No. 4.] DAWSON — POST-PLIOCENE. 393 



Long, (apice docollato) -82, long, spir, -32, lat. -76. poll. Div. 

 90^. 



Hah. Montreal, in strato glaciali, fossilis, rarissime reperta. 

 Mus. Dawson, McGill Coll., Nat. Hist. Soc. 



Dr. Carpenter adds the following remarks : 



While almost all the other drift fossils are of species still living 

 in the neighbouring seas, this is not known, even generically, to 

 be at present in existence. It is hard to pronounce satisfactorily 

 on its relationships. In its thin, coated shell it resembles Velu- 

 tina ; the striae and loose whirls recall Naticina ; the straight 

 pillar lip reminds us of Fossarus; while the umbilicus and 

 rounded base, with entire mouth, best accord with the Natica 

 group. With Trichotropis and its congeners I can see no resem- 

 blance. One remarkable feature in all the specimens is the de- 

 collation of the upper whirls, seen even in a nearly perfect young 

 specimen, -2 across ; other young specimens, even smaller, have 

 only one whirl and a half remaining. The broken portion is 

 filled up not so mnch by a septum as by a solid thickening. The 

 separation of the whirls is complete from the beginning ; and 

 although, in the parietal portion, they are closely appressed, the 

 smooth and somewhat glossy epidermis is distinctly seen between. 

 The fracture of the mouth in most of the specimens, enables this 

 feature to be distinctly observed ; and would also reveal the 

 " internal groove " and columellar callosity ascribed to Torellia, 

 did any such exist. 



The straightening of the inner lip, at an angle of 30° from the 

 axis, makes the umbilicus by no means large (for a Naticoid 

 shell) when viewed from the base in the line of the pillar ; but 

 the same cause enlarges it within, recalling the adult appearance 

 of Amphithalamus. The flattening of the upper portion of the 

 whirls gives the shell somewhat of an lanthinoid aspect. 



While the analogies of the shell point in so many different 

 directions, it is impossible to assign it even to its family group. 

 It is to be hoped, however, that the dredge will yet reveal its 

 existence in a living state. 



The above species may be supposed to resemble Torellia ves- 

 tita, Jeffreys, from Norway. Our specimens differ however in 

 form, as above noted, and also in the absence of the tooth in the 

 inner lip, and in the smooth epidermis. 



The shell in question presents the very unusual character of 

 having the whirls appressed, yet quite disconnected ; the smooth 



