322 PYRAMIDELLID^. 



towards the lower right-hand corner, hence the appearance 

 of obliquity which it presents ; the final declination is 

 abrupt but well rounded. The capacious aperture fills 

 nearly the whole of the ventral area, yet does not disclose 

 the internal gyration. The peristome is complete, and 

 of a rounded oval figure, of which the pillar end, however, 

 is blunted. The acute and simple outer lip is much pro- 

 duced, disposed to expand, and everywhere arcuated ; the 

 throat is quite smooth, and much shining. The pillar lip 

 is flattened, shelves inwards, and is devoid of sculpture or 

 canal ; it is of a narrow sublunar shape, the incurvation 

 of it is very trifling above. There is no vestige of any 

 umbilicus. Such is the minuteness of its size, that our 

 largest example only measured the ninth of an inch 

 across. 



We found Otina oils alive many years ago in crevices of 

 rocks between tide-marks, associated with Kellia rubra 

 and Conovulns alhus at Kirk Santon Head, in the Isle of 

 Man. We were at once struck by its dissimilarity from 

 Velutina, by its horn-less head, and its curioiis Succinea- 

 like aspect. Since then Ave have never had an opportunity 

 of examining it, but are enabled from the published notice 

 by Mr. Alder, and from more extended valuable notes com- 

 municated by Mr. Clark, to detail its characters. The 

 animal is of a hyaline white hue, very thick and large as 

 compared with the size of its shell. The mantle is simple 

 and not reflected on the shell. The head is large and 

 broad, and bears two almost obsolete triangular tentacles 

 or auricular processes. The eyes are set at the upper 

 bases of these ; they are large and black. The mouth is 

 inferior and vertically cloven ; it is furnished with dis- 

 tinct jaws and a short denticulated tongue. The foot is 

 oblong, divided by a transverse groove across its centre, 



