LOBIGER. 31 



furnished at the angles with two ear-shaped tentacles, but 

 the labial tentacles, so conspicuously developed in Aply- 

 sia, appear to be entirely wanting. The side-lobes of the 

 foot, which some regard as the mantle, are separated in 

 the middle of the back, so as partially to expose the invo- 

 lute Bulla-likc shell ; the tail is very long and compressed, 

 and the orifices of the organs of reproduction are close 

 together, in a single tubercle, near the right tentacle. 



Species of Lophocercus. 

 pcllucidus, A. Adams. Sieboklii, Krohn. 



Genus LOBIGER, Krohn. 



Body produced posteriorly into a long, pointed tail, 

 covered with papillae. Foot with the natatory appendages 

 in the form of dilated, rounded lobes, two on each side. 



Shell thin, transparent, covered with an epidermis ; 

 spire rudimentary, in the form of a protuberance directed 

 towards the left. 



Ex. L. Philippii, Krohn, pi. 59, fig. 2. Shell, L. 

 Philippii, fig. 2, a. 



In general organization the animal of this genus closely 

 resembles that of Lophocercus, from which, however, it 

 differs in the body being provided with four lateral, 

 expanded, wing-like lobes, and in the simple, ovate shell, 

 which is not elastic and involute as in that genus. 



Species of Lobiyer. 



Cunnngii, A. Adams. Philippii, Krohn. 



Krohnii, A. Adams. 



