70 CRETACEOUS GROUP 



BRACHIOPODA. 

 Terebratula, Lam. 



1. T. Harlani, (S. G. M.) PI. iii, fig. 1, and pi. ix, 

 fig. 8 and 9. 



Amer. Journ. Science, vol. xviii, pi. iii, fig. 16 ; Journ. 

 Acad. Nat. Sciences of Philad. vol. vi, pi. iii. 



Specific character. Thick, elongated ; upper valve convex, 

 biplicated at the margin ; lower valve very convex, with a lon- 

 gitudinal ridge, and slight lateral depressions ; beak incurved. 



Length, from one to three inches. 



Abundant at Egypt and other places in New Jersey, in 

 the arenaceous strata. 



Far. A. Rectilateral. PI. ix, fig. 9. 



Var. B. Discoidal. PI. ix, fig. 8. 



Notwithstanding the difference between var. B. and 

 the usual forms of T. Harlani, I am not willing to consi- 

 der it a distinct species, inasmuch as it appears to pass by 

 insensible degrees into the other varieties. It is figured 

 in the Journ. Acad. Nat. Sciences, vol. vi, pi. iii, fig. 7 

 and 8, and there provisionally referred to T. perovatis, 

 of Sowerby, from which it is altogether distinct. If it 

 should not prove to be a variety of T. Harlani, I propose 

 for it the name of T. camella. 



2. T.fragilis, (S. G. M.) PI. iii, ^. 2. 



Specific character. Very thin, fragile; rectilateral, sides 

 parallel ; upper valve sub-convex, with two longitudinal 

 ridges almost its whole length, forming a deep biplication ; in- 

 ferior valve very convex, with a prominent central ridge and 

 corresponding lateral depressions. 



