332 



POPULAR CGNCHOLOGY. 



Gryphus. Megerle v. Muehlfeld. — Shell separated 

 from the foregoing solely because the inner scaffold forms 

 a complete ring, which is borne upon two stalks, and in 

 the lower valve there is no spur with a middle rib. 



The type of this genus is T. vitrea from the Medi- 

 terranean ; the genus is scarcely distinguishable from the 

 last. 



Terebratulina. D'Orb, — Shell free, of a punctured 

 texture, oval, oblong, depressed; the larger or dorsal 

 valve is more strongly arched than the ventral ; the boss 

 is projecting, straight for the most part, obliquely notched 

 at the end ; without distinct area ; the under valve has a 

 distinct boss, and on each side an ear as in Pecten ; the 

 hole in the boss is oblong, and takes in the whole ex- 

 tremity, from whence it continues to the boss of the under 

 valve without forming a deltidium ; the hinge is as usual ; 

 the inner scaffold is supported by a lateral apophysis on 

 each side, which springs from the hinge, converging in- 

 wards, from which rise two arms meeting twice so as to 

 form a short tube; the upper surface is covered with 

 forked ribs. — ? species ; also fossil. 



This genus is separated from Terebratula by having no 

 deltidium, a simple inner scaffold and forked ribs ; from 

 Terebratella by the absence of area and deltidium, the 

 longitudinal beak hole, and the want of the middle plate in 

 the interior. The type is T. caput serpentis from the 

 European seas. 



Terebrirostra. Orb.— Shell free, of a punctured 

 texture, elongated, inequivalve, the upper valve being 

 very much longer than the other ; the beak is very long, 

 and under it there is a long flat smooth area, extending 

 from the hinge to the point; the under valve is oval, 

 short, sometimes only a third part the length of the upper ; 



