1890.] NATURAL SCIENCES OF PHILADELPHIA. 143 



Forms representing at least 14 genera occur in all the clays be- 

 low 1,095 feet while about five of the same generic forms have been 

 observed between 430 to 480 feet. The genera are as follows : — 



Nodosaria, Dentalina, Cristellaria, Robulina, Nonionina, Rota- 

 Una, Rosa/lna, Bulemlna, Uvigerlna, Amphistigina, Guttulina, Bil- 

 oculina, Triloculina and Textularia. 



It now remains to enumerate the fossils, excepting the microscopic , 

 ones already listed. Although generally in very fragmentary con- 

 dition, it has been possible to name 82 species of mollusks, exclusive 

 of 8 forms determinable by genera only. Besides the mollusks there 

 were representatives of eleven other life forms, among them a few 

 varieties of corals and a bone belonging to an animal of the 

 crocodilian order. Identifications of all the fossils, excepting the 

 microscopic, have been very kindly made by Prof. A. Heilprin. 

 Specimens obtained from both wells No. 1 and No. 8 are included. 

 In those from No. 3 the depth where each was found is given ; in 

 No. 1 this is not known. Of the 41 molluscan forms from well 

 No. 1 and noted in the Academy's Proceedings for 1889, all but 12 

 were again found in well No. 3. 



The list is as follows : 



Anomia probably ephippium. 



Arca centexaria. 



A RCA subrostrata, 682. 



Arca (idonea?) 



Arca lienosa, 725. 



Arca plicatura. 



Artemis acetabulum. 



ASTARTE obruta, 682. 



ASTARTE PERPLANA, 700. 



AsTAKTE Thomasii, 875. 



AsTARTE CUNEIFORMIS, 695. 



AsTARTE compsonema, 725, 875. 

 Amphidesma subreflexa, 750. 

 Cardita granulata, 682, 750, 885, 1180. 

 Cardita arata. 

 Cardium creticuloides "I 



or LEPTOPLEURA, j 



Cardium laqueatum, 700. 

 Corbula cuneata, 750. 

 Corbula idonea, 700. 



