40 PALEONTOLOGY OF NEW JERSEY. 



Genus LITHOPHAGA Bolten. 



LlTHOPHAGA SUBALVEATA. 

 PL V, fig. 9. 



Lithophaga subalveata Conrad: Am. Jour. Conch., vol. 2, p. 73, PI. iv, fig 4. 

 Lithodomus subalveatus Heilprin: Proc. Acad. Nat. Sci. Phil., 1887, pp. 397 and 402. 



"Oblong, very thin and fragile, ventricose, posterior side produced, a 

 slight wide furrow marks the umbonal slope, on and behind which are con- 

 centric grooves and lines; basal line slightly emarginate or contracted." 

 (Conrad, op. cit). 



This is one of the few species described from New Jersey which I 

 have not personally seen. Mr. Conrad says that u a single specimen was 

 found penetrating the shell of Ostrea percrassa, Conrad." And Prof. Heil- 

 prin cites, in one of his lists, a form of Lithodomus sp.l I have seen a 

 few of the cavities in 0. percrassa Conrad, from New Jersey, which I sup- 

 pose may have been the burrows of this species, but no shells were in 

 them. Consequently I have, in this case as in others, copied Mr. Conrad's 

 figures of the species. 



Locality: Mr. Conrad gives "Shiloh, Cumberland County, N. J.," as 

 the locality. 



HOMOMYARIA. 



Family ARCm.E. 



Genus STRIARCA Conrad. 



Striarca Conrad: Proc. Acad. Nat. Sci. Phila., 1862, p. 290. 



Mr. Conrad describes the genus in the following language: " Equi valve, 

 radiately striate, closed; hinge area transversely striated, and also the epi- 

 dermis above it; hinge line dilated and curved at the ends; teeth divided 

 into oblique hollow cross plaits." Area centenaria Say, is mentioned as the 

 type. He further states that "the remarkable teeth of this genus dis- 

 tinguishes it from all other genera of the Arcidae; the plaits are hollow with 

 parallel laminar sides." 



