NOMENCLATURE. 31 



Stride. See above. 



ahlreviatce. Abbreviated ; not extending to the 

 margin. 



lifarice. Bifarious ; diverging. 



recurvaice. Recurved; elevated, membranaceous; 

 tending towards the apex. 



incsquilineatcB. Inaequilinear ; not parallel. 



Sulci. See above ; sometimes they are used, 

 though perhaps improperly, to signify the 

 same as Costce, Ribs. 



fornicaii. Arched ; covered with arched scales. 



Testa. See above. 



antiquata. Antiquated ; longitudinally sulcate or 

 furrowed, but interrupted by transverse 

 accretions, as if lesser valves were periodi- 

 cally added to the apex or beak. 



aurita. Eared; the hinge produced on either 

 side the beaks into a flat prominent an- 

 gle. 



larbata. Bearded ; superficially covered with rigid 

 hairs. 



compressa. Compressed ; the valves flattened, 

 and the bosses less than usually gibbous. 



