510 A. W. GRABAU PAL>: JZOIC I>ELTA DEPOSITS OP KORTH AMERICA 



Herkimer pool is well restricted and its faunule can not be traced very 

 far toward the west: the Buffalo E. locust ris, however, appears aloi le 

 far east as Union Springs, Cayuga County, and as far west as Bertie. 

 Ontario. Another difference in these faunas is the preponderating great 

 size of all the species in the Buffalo pool and, by contrast, the small size 

 of and abundant young among the Herkimer County - ... 



That the smaller creatures lived in conditions of shallower water is 

 evinced by the sun-dried and cracked rock surfaces of their matrix, while 

 such evidences are wanting in the Buffalo pool/' 110 . . . Another strik- 

 ing fact is the total absence of Eurypterids from the Bosendale cement 

 rock, which is essentially the same type of rock and of the san _ 

 the Bertie, lying, as does the Bertie water-lime, just below the Cobleskill. 

 The Bosendale. however, occasionally contains marine organisms and is 

 immediately preceded as well as succeeded by fossiliferous marine lime- 

 stones. Eurypterus remipes, the common form of the Beitie water-lime 

 in the Herkimer pool, just below the Cobleskill. has also been obtained 

 from the Bondout water-lime above the Cobleskill at Seneca Falls. Seneca 

 County. Xew York. This clearly shows that the Cobleskill marks only a 

 temporary marine invasion between two periods during which water- 

 limes were forming and during which the same species of Eurypterids 

 were preserved in these water-limes. From a horizon believed to be near 

 the Bertie at Selins Grove .Junction. Pennsylvania, some f ragmen : - 

 Eurypterus like E. remipes have been obtained, and from a lower horizon, 

 probably in the Lower Monroe (upper part of the McKenzie formation) 

 near Hancock, Maryland, fragments suggesting a Ptervgotus have been 

 reported. 



In the highest Siluric horizon of Xorth America, the Manlius lime- 

 stone of N^w York, a single species of Eurvp terns, E. micro phtha 

 HalL, has been found. The type, a separate carapace, was obtained from 

 a boulder near Cazenovia. Madison County. New York. A nearly perfect 

 specimen was obtained from a drift boulder near Syracuse. Xew York. 

 also referred to the Manlius. Several earapac •tained from the 



Manlius in situ near Litchfield. Cranes Corner, Herkimer County, and at 

 Manlius village. ••From this it appears that there is a continuous water- 

 lime bed near the top of the Manlius formation extending from Onon- 

 daga County to Albany County and the species seems to be confined to 

 this layer.'" :: 



The Ludlow or Upper Siluric of England and Scotland shows a good 

 representation of Eurvpterids. there being altogether 4 genera an 



uo Clarke and Ruedemann. loc. cit.. i . - 

 ^Clarke and Ruedemann. loc. cit., p. 194. 



