OTINA. 223 



horny ; operculum none ; shell depressed, nearly 

 ear-shaped ; spire small, lateral ; aperture large ; 

 peristome nearly continuous ; pillar arched. 



On the sea-coast, just above or just within the 

 edge of the tide-line. The animals walk by the 

 alternate motion of the two sections of the foot and 

 of the lower surface of its large broad head. 



This animal was first described as belonsiino; to 

 the genus Helix. Dr. Fleming referred it to Velu- 

 tina ; and after examining the animal, I separated it 

 as a section of that genus under the name of Otina. 

 Mr. Clark adopted it, and placed it, with some doubt, 

 among the genera of Auriculidce, which he considers 

 pectinobranchous. Messrs. Forbes and Hanley refer 

 it to Pyramidelladce, describing the animal as having 

 "an armed tongue and jaws, and branchial plume 

 single." But in 1854 I showed that the animal, 

 instead of having gills, respired free air in a closed 

 branchial cavity, and had teeth like other Pneumo- 

 nohranchiata, and compared it with Auricula. Dr. 

 Pfeiffer forms for it a small sub-family of OtinincB 

 in Auriculidce; but the form of the animal, and 

 especially of the tentacle and the shell, bears much 

 more affinity to the family Limnceadcs. 



100. 1. Otina otis. — Shell depressed, semi-ovate, 

 rather solid, very slightly striated, covered 

 with a thin periostracum, rather shining 

 brown, often eroded ; spire minute ; whorls 

 2 \, the last somewhat compressed ; aperture 

 nearly horizontal, ovate oblong; peristome 

 nearly continuous, with the pillar edge liver- 

 coloured. 



