26 Bulletin 5 296 



78 TESTACEOUS FORMATION 



By permission of my very esteemed and learn- 

 ed friend, Mr. Thomas Say, I add, as a valuable 

 addition to the above paper, his notes of various 

 shells composing that aggregated mass, viz. 



Fossil shells found in a shell mass fjvin Anastasia Island. 



1. Arca pexata, nobis. It is not a little singular that this 

 shell, and the six next following, so common on our coast at 

 the present day, should be found here in a fossil state. 



2. Arca po?ide7vsa, nobis. This shell also, which is very 

 common in the fossil state, is found recent on the southern 

 coast. But I have not found any fossil specimens so large 

 as a recent one in my cabinet. 



3. Arca incongrua, nobis. Several small fragments of a 

 shell, which I believe to have been identical with the recent 

 species of this name, occurred in the mass. 



4. Arca transversa, nobis. A tolerably perfect young shell, 

 and many fragments of full sized individuals ; but this spe- 

 cies is not so abundant as either of the preceding. 



5. I^uTRARiA canaliculata , nobis. Three small portions of 

 [J. A. N. S., Phila., ist Ser., Vol. IV, 1824.] 



