Lamarck’s Genera of Shells. 33 
2. Gastrochena*, 
Shell bivalve, equivalve, almost wedge-shaped, very gaping; 
anterior aperture very large, oval, oblique; hardly any poste- 
rior aperture. Hinge linear, marginal, toothless. No accessary 
valves. 
Type. Gastrochena cunetformist. Pholas hians. Chemn. 
Sheli wedge-shaped, thin, somewhat transparent ; striz of 
the valves transverse, arched. 
Isle of France. Pl. iv. Fig. 25. 3 Species. 
3d Family. 
SoLtenacea. (3 Genera.) 
Shell transversely elongated, no accessary pieces, gaping 
only at the lateral extremities. Ligament external. 
The solenacea bury themselves in the sand, but do not per- 
forate stone or wood. 
1. Solent. 
Shell bivalve, equivalve, transversely elongated, gaping at 
both ends; beaks very small, not projecting. Cardinal teeth 
small, varying in number, sometimes none, seldom diverging, 
more rarely inserted in little pits. Ligament external near the 
hinge. 
Animal with a mantle, closed in front; protruding, at one 
extremity of the shell, a subcylindrical foot ; and at the other a 
short tube, containing two tubes united. 
The solens live on the sea-shore, burying themselves per- 
pendicularly in the sand, sometimes to the depth of two feet, 
ascending and descending by means of the muscular foot, at 
the lower extremity of the shell. 
Type. Solen vagina§. Idem. Linn. 
Shell linear, straight; one end marginated, or thickened ; one 
cardinal tooth in each valve. European, American, and Indian 
Seas. Pl. iv. Fig. 26. 21 Species. 
2. Panopea||. 
Shell equivalve, transverse, unequally gaping at the sides. 
* From yaclup, the belly, and xawa, to gape. t Widge shaped. 
} Zwdnv, a pipe, or tube. § Sheath. 
|| Mav, omne, et omaisv, foramen, indicating the great gapivg of the shell. 
Vor. XIV. G 
