FAUNA OF THE CLIFFWOOD CLAYS 329 



vexity, 5 mm . The regions of the carapace are clearly marked 

 by more or less deeply impressed furrows, as shown in the 

 accompanying illustrations. This is one of the common forms 

 in the Cliffwood fauna, and is the only crustacean which has 

 been observed in the fauna of the Woodbury clay. 



A sandstone mass was collected on the beach at Cliffwood, eighteen 

 inches in length by twelve inches in breadth and perhaps three inches 

 thick, completely filled with fossils. This mass of sandstone was not 

 in situ, and, being different in its lithologic characters from any 

 material imbedded in the clay at this point, it may have been trans- 

 ported to this locality from elsewhere. It is-, however, somewhat simi- 

 lar in its lithologic characters to certain sandy, fossiliferous nodules 

 occurring in the clay at the pits of the Cliffwood Brick Company, a 

 little over a mile distant on Whale Creek. The fauna yielded by this 

 sandstone undoubtedly indicates its Cliffwood age, although several 

 species occur which have not been observed elsewhere. The species 

 of fossils identified are as follows : 



PELECYPODA 



1. Breviarca sp. undet. This is apparently the same species as 

 that noted from the fauna of the crustacean nodules. 



2. Trigonarca n. sp. ? This is one of the common species of the 

 fauna, and is apparently undescribed. It has the form of a 

 small Idonearca, but is less convex than most species of that 

 genus and has a different hinge structure. 



3. Trigonarca n. sp. ? This is a larger species than the last, and 

 the hinge bears a much larger number of teeth. Neither of the 

 species has been observed elsewhere. 



4. Nuculana protexta (Gabb) ? The specimens of this species 

 are poorly preserved, but they seem to be specifically identical 

 with those from the crustacean nodules which have been identi- 

 fied as N. protexta. 



5. Yoldia cf. evansi M. & H. This is a rather common species in 

 the fauna, and is closely allied to, if not identical with, Y. evansi 

 from the Fox Hills beds of the West. 



6. Cardium sp. undet. This species can be identified with none 



