- 43 - 



Remarks . - This small and delicately sculptured siDecies is 

 represented by a number of valves. The eharacteristio features 

 are the weakly, but obviously, impressed pseudo-limule, the rel- 

 atively strong sculpture and the moderately inequilateral o.tline. 

 F. tenuisculpta ":abb (1), a Santo Domingo Oligooene form, is more 



(1). Trans. Am. Philos. Soc, new ser. , vol. 15, p. SoS, 1875. 



elongated and has weaker and finer concent rio sculpture and strong- 

 er radial striations. Guppy has described two species, IT. vieta (2) 

 and IT. bacca^:a (5) from the Pliocene of iTatura, '""rinidad; vieta is 



(2). Proc. 3ci. Assoc. Trinidad for 1867, p. 174; Geol. Kag., 



Decade 2. vol. 1, p. 443 (check list); vl. 18, fig. 8, 1874. 

 Dall , (Trans. V.'agner ?ree Inst. Sci., Philadelphia, vol. 3, 

 pt. 4, p. 577, 1898) has placed this st)ecies together v7ith 

 tenuisculpta Gabb in synonymy v;ith crenulata Hinds, but 

 the two fossil species, at least, are -'istinct from each other. 



smaller, higher, more oblique, more inflated and is without the 

 posterior impressed area, v.^.ile b ace at a is larger, more oblique, 



(3). Idem, 1857, p. 174; idem, 1874, p. 443, pi. 18, fig. 7. 



more inflated and has lower ambones, no posterior area, finer 

 sculpture and more persistent radial striae. 



