84 Lamarck’s Genera of Shells. 
One conical cardinal tooth in each valve, and near it a short, 
ascending, compressed callus, not projecting outwards. Liga- 
ment external, on the longer side of the shell, fixed on the 
ealli. 
The panopza differs from the glycimeris, by having cardinal 
teeth, and by the ligament being on the longest side ; from the 
solen, by the greater projection of the beaks, and from the 
mya, by the ligament being external. 
1 Species. Panopea Aldrovandi*. (Mya Glycimeris. Linn.) 
Mediterranean. Pl. iv. Fig. 27. Gmelin. 
3. Glycimeris. 
Shell transverse, very gaping on both sides, Hinge callous, 
without teeth. Nymphe projecting outwards. Ligament ex- 
ternal. 
The glycimeris differs from the solen and the saxicava, by 
having the ligament on the shortest side of the shell, and from 
the solen also further, by having no hinge tooth. 
Type. Glycameris Stliquat. 
Shell transversely oblong, epidermis black; nates eroded ; 
valves internally thickened by a callous disc. PI. iv. Fig. 28. 
North Seas. 3 Species. 
Ath Family. 
Myaria. (3 Genera.) 
Ligament internal. One large spoon-shaped tooth, either on 
both valves, or only on one, to the cavity of which the ligament 
is attached. Shell gaping at one end, or at both. 
1, Myat. 
Shell bivalve, transverse, gaping at both ends. One large 
cardinal tooth on the left valve, compressed, broad, somewhat 
rounded, projecting almost vertically. A cardinal pit on the 
other valve. Ligament internal, short and thick, inserted in 
the projecting tooth, and the corresponding cavity of the oppo- 
site valve. Animal with a mantle, closed before, a short, com- 
pressed, and rather thick foot, at one extremity ; at the other, 
* Aldrovandus. + Bean pod. + Mus, amuscle. 
