GRYPMiEA, Delamarck . 
Gem. Char. A free (except when very young) 
unequal -valved, inequilateral bivalve; larger 
valve involutely curved, concave, lesser valve 
Saltish, beakless. Hinge a transversely striated 
pit, containing an internal ligament, without 
teeth or crenatures. 
xMESSBBm mmm . 
The lamellar structure of the Gryphites and their texture 
is much the same as that of the Ostracites, the hinge is 
also of the same nature; but the general form has afforded 
Delamarck a distinguishing character; how far this is 
sufficient, I leave others to judge. The general per- 
pendicularity of the hinge, the restriction on the right 
side, and the concavity of the smaller valve may assist. 
The length of most of the species is greater than the 
width ; the larger and lower valve is very concave, gra- 
dually curved into a large, more or less involute beak, 
along which runs one side of the pit holding the hinge 
cartilage: this side is consequently curved. The lesser 
valve is flat or convex within, and forms a kind of lid; 
the part to which the hinge cartilage is attached in this 
valve, is flat and perpendicular. The very young shells are 
nearly flat and attached to other bodies, of which they 
take the impression, through both valves; when they are 
full grown they lose their attachment, and the impression 
remains upon the beak of one valve and upon that part of 
