227 



which, if proved persistent by farther investigations, may 

 be usefully designated as subdivisions of the genus.* 



The Stroph. striata was described in vol. n, Pal. N. Y., from 

 very meagre material, consisting of flattened valves in the 

 shale, and its similarity to S. subplana may have led to 

 some doubt regarding its distinction. The Waldron speci- 

 mens which have afforded the interior of both valves, prove 

 it to be a very distinct and well marked species. 



It is remarkable that the Spirifer sulcatus, so common in 

 New York, has not been found at this locality. 



There is a species of Pentamerus resembling the P. 

 (Atrypa) trevirostris of the Niagara group in New York, but 

 it is larger, and mora nearly approaches the P. verneuili of 

 the Lower Helderberg group, and farther stud}' may prove 

 it to be distinct from either. 



GASTEROPODA. 

 Platyostoma niagarensis. 



This species in numerous individuals presents the charac- 

 ters of Platyostoma, while by insensible gradations it passes 

 into Platyceras. 



CRUSTACEA. 

 Calymene niagarensis. 



Homalonotus delphinocephalus (of this species two frag- 

 ments only have been seen). 

 Lichas boltoni ? 

 Illaenus barriensis (rare). 



There are a few specimens of Lamellibranchiata of two 

 species ; one of which appears to be identical with a New 

 York species, and the other with one known in the Niagara 

 group of Wisconsin. 



Two or more species of Orthoceratites have been found ; 



* For farther observations upon this subject see Sixteenth rfnnual Report 

 on the New York Cabinet of Natural History. 



