28Q Organic Remains of the Ferruginous 



TELLINA. 



A small, handsome shell, in general appearance not unlike T.pu- 

 nicea, is found near Arneytown, N. J. 



AVICULA. 



Very perfect casts of a small species. 



PECTUNCULUS. 



A few indeterminate casts. 



PINNA. 



Casts, in fragments, resembling the P. tetragona of Sowerby, pi. 

 313, fig. 1. 



TEREDO. Lin. 



T. antenauta ? (Sowerby.) The teredo is abundant throughout 

 the marl region. It is constantly found in the lignite of the Chesa- 

 peake and Delaware canal, where trunks of trees are pierced by 

 it in every direction. The casts of this fossil are frequently half an 

 inch in diameter. Sometimes these casts consist of pyrites. In the 

 calcareous marls of New Jersey, the shelly tube of the Teredo is re- 

 placed by crystallized carbonate of lime. 



VENUS. Lin. 



A cast, about half an inch in diameter, with fifteen or twenty striaj 

 radiating from the hinge to the margin. This is probably a Veneri- 

 cardia of Lamarck. 



ECHINIDE^. 



SPAT ANGUS. Lam. 



1. A species with five deep sulci, and closely allied to the well 

 known European chalk fossil <S. cor marinum, as figured in Parkin- 

 son's Org. Rem. Vol. III. pi. 3. fig. 11. It is abundant in the calca- 

 reous formation of Gloucester county, New Jersey ; the specimens 

 are not casts, but on the contrary have their shell or crust replaced by 

 carbonate of lime, and are as perfect as the European chalk echini. 

 They vary in magnitude from the size of a filbert to an inch and a 

 half in diameter. 



2. Another species much more compressed than the preceding, 

 but otherwise resembling it, is common at the Deep Cut of tlie Ches- 

 apeake and Delaware canal. 



