VENUS. 413 



cllne much forward. The heaks, which are very distinct 

 and acute, are preceded by a large impressed and well-de- 

 fined lunulc, which is more or less heart-shaped and devoid 

 of any sculpture, unless we regard as such the concentric 

 lines of growth. The ligament, which is of a moderate 

 size, not at all concealed, and usually of a fulvous or yel- 

 lowish hue, is seated in a peculiarly large moderately ex- 

 cavated area, which is almost smooth, and not limited by 

 any carination, though its boundaries are more or less an- 

 gulated. In this excavation the breadth, as well as the 

 bevelling of edges, is equal in both valves ; but the left 

 valve is decidedly the smoother. 



The interior is of an uniform white ; the hinder teeth are 

 so thin as occasionally to become almost obsolete in one or 

 both valves : the inner margin is very finely crenulated ; 

 the i^allial sinus is moderately large. 



The length of a fine example is nearly an inch and a 

 half, and the breadth about an inch and a fifth. 



Having had ample opportunities of observing the animal, 

 we can confidently assert the distinctness of its characters, 

 as well as the shell, from those of the true (jallina, of which 

 a good representation has lately been given by Deshayes in 

 the " MoUusques d'Algerie." The two species differ most 

 materially in the structure of their siphons. In our British 

 one the siphonal tubes are united to their extremities; in 

 the Mediterranean form they are not only much shorter, 

 but diverge considerably : their orifices in the former are 

 fringed with few and very inconspicuous cirrhi ; in the 

 latter the cirrhi are numerous and conspicuous. The animal 

 of strlatula may, indeed, be regarded as an aberrant form 

 in its genus, whereas that of gallina presents the ordinary 

 characters of its congeners. 



The body of the animal of Venus striaiula partakes of 



