20 THE HABITAT OF THE ETJRYPTERIDA 



Seven specimens of Lingula sp. Hall occur on one of the slabs. 

 Leperditia alta and a large number of pelecypods of the genus Gonio- 

 phora, but labeled Leperditia alta occur on a slab which probably 

 does not come from the Buffalo region, but is more likely from Ohio, 

 judging from the lithological character. Finally, there are a number 

 of specimens of Ceratiocaris acuminata associated on the same slabs 

 with the eurypterids and showing a preservation as perfect as theirs, 

 these being the only fossils which do show this. Number 11453 E 968 

 contains Eurypterus lacustris and a large specimen of Ceratiocaris 

 acuminata, the former with head shield and body separated, but both 

 beautifully preserved. The plant remains are important, for many 

 of the specimens of Eurypterus are found lying embedded in Butho- 

 trephis lesquereuxi, and in one case there is a large mass of Butho- 

 trephis at the side and on top of a Eurypterus (13329 E 1657). (Some 

 of these specimens of Buthotrephis are now regarded as graptolites.) 

 There are three specimens of the plant ? form, Chondrites gramini- 

 formis, two of which are excellently preserved (13273 E 1602 and 

 133 1 2 E 1641 Pohlman's type 4 ). At Waterville, Oneida County, New 

 York, a small scorpion Proscorpius osborni Whitfield has been found 

 in a good state of preservation in the Bertie waterlime. 



A remarkable fact in connection with the occurrence of the euryp- 

 terids in the Bertie 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 forms in common, but it is 

 certainly a significant fact that the abundantly represented species 

 of the two areas are distinct, when the horizon is the same, and the 

 localities only a few hundred miles distant. The following list gives 

 the specimens for each pool, representative or identical species being 

 apposed (39, 92 footnote): 



Buffalo Pool Herkimer Pool 



1. Eurypterus lacustris 1. Eurypterus remipes 



2. E. lacustris var. pachychirus 



3. E. pustulosus 



4. Eusarcus scorpionis 



5. Dolichopterus macrochirus 5. Dolichopterus machrochirus 



6. D. siluriceps 6. D. testudineus 



7. Pterygotus buffaloensis 7. Pterygotus macrophthalmus 



8. P. cobbi ' 8. P. cobbi 



9. P. grandis 9. Proscorpius osborni 



< Figured in Buf. Soc. Nat. Hist. Bull., Vol. V, p. 31 (220). 



