GALEOMMA. 



mal, which he has heen enabled to make from specimens 

 collected on the coast of Sicily. 



" The mantle of the animal is flat and stretched 

 across the gape of the ventral edge of the shell, where it 

 is furnished with a fringe that is attached to the epidermis 

 of the shell, as in Gastrochsena, it has^ however, only a 

 short linear contracted opening at the posterior part of the 

 gape ; the foot is squarish, compressed, its base linear, 

 truncated, of the size of the groove in the mantle. The 

 structure of the mantle and foot of this animal is most 

 like that of Gastrochaena, but it differs from that animal 

 in not being provided with an elongated siphon, and the 

 shell which approximates somewhat in form to some of 

 the most gaping Gastrochaenee is at once distinguished 

 from that genus by the umbones being more central, by 

 the interior being destitute of any siphonal impression and 

 by its having an internal cartilage. The shell is covered 

 with a thin membranaceous epidermis which is easily 

 rubbed off when fresh, and thus the shell is left white, 

 semitransparent and marked with very fine slightly raised 

 radiating striae, the umbones are semiglobose, smooth, 

 with a distinct circumscribed edge, the ligament is ex- 

 ternal, linear, expanded over the outer surface of the 

 rather narrow cardinal facets, with the cartilage placed 

 in a small, short triangular pit immediately under and 

 slightly prominent beneath the umbones ; the impres- 

 sions of the adductor muscles are roundish and distinct, 

 the front one has a smaller muscular impression above it, 

 and there are two indistinct impressions extending nearly 

 all along the arch of the cardinal edge." 



Fig. 1. 2. 3. Galeomma Turtoni. 



4. 5. ■ - Mauritianum. 



