DISTRIBUTION AND OCCURRENCE OF EURYPTERIDS 509 



Eurypterid remains there occurs an abundance of plants, referred to By- 

 throtrephis lesquereuxi. The habitat of this plant is unknown, but if 

 marine it certainly did not exist in deep water, but was most probably 

 similar in habitat to the eel-grass of the modern shore. The phyllocarid, 

 Ceratiocaris acuminata, is of fairly common occurrence, and at Water- 

 ville, New York, a small scorpion, Proscorpius osborni Whitfield, prob- 

 ably a terrestrial form, has been found perfectly preserved. A remark- 

 able fact 108 in connection with the occurrence of the Eurypterids in the 

 Bertie water-lime is their distribution in two distinct basins or pools, the 

 "Herkimer pool" on the east and the "Buffalo pool" on the west. These 

 "pools," while prolific in species and individuals, have, however, only two 

 species in common, so far as published' data show. Further search may 

 reveal more common forms, but it is certainly a significant fact that the 

 common species of the two areas are distinct, when the horizon is the 

 same and the localities only a few hundred miles distant. The following 

 lists give the species for each pool, 109 , representative or identical species 

 being apposed : 



Ilei-kimer pool, Buffalo pool. 



1. Eurypterus remipes '. 1. Eurypterus lacustris 



2. E. lacustris var. pachychirus 



3. E. pustulosub 



4. Eusarcus scorpionis 



5. Dolichopterus macrochirus 5. Dolichopterus macrochwus 



Ga. D. siluriceps 

 6&. D. (?) testudineus 



7. Pterygotm macrophthalmus 7. Pterygotus buffulocnsis 



8. P. cobbi 8. P. cobhi 



9. P. grandis 

 10. Proscorpius osborni 



"The species common to both are Dolichopterus macrochirus and 

 Plerygolus cobbi, both of which arc quite rare, while the predominant 

 species in both places are unlike. It is no! believed thai these differences 

 necessarily express distinct stratigraphic horizons, as both lie Dear the 

 lop of the walcrdime succession, but rather indicate original regional 

 separation into distinct lagoons or pools . . . which we may assume to 

 have been synchronous. There is, in the face of the difference suggested, 



a certain degree of approximation in the two, expressed by such vicarious 

 species as E. remipes and lacustris, P. macroph I halm us and buffaloensis, 



which may well mean distinctions due to geographic isolation. The 



ws Clarke and Ruedemann, loc. clt., i>. !>l\ fool note. 

 i<» [bidem. 



