BUFFALO SOCIETY OF NATURAL SCIENCES 57 



of the problem. "The Eurypterid fauna also occurs in the mud 

 layers in the Shawangunk conglomerate, which hardly admits of any 

 other interpretation than deposition by torrential rivers. This would 

 make the urypterid fauna a fresh-water fauna, an interpretation 

 which best corresponds with the distribution of these fossils geologi- 

 cally as well as geographically. The Salina series is best understood 

 as a desert deposit. The absence of organic remains (with the ex- 

 ceptions noted), known to be abundant in all modern salt deposits 

 of sea-margin origin; the thickness of the salt beds; their limitation 

 to circumscribed basins, the red color of the lower shales, their mud- 

 cracks, all point to a continental origin" (84, 245). Clarke in refer- 

 ence to this fauna says: "Our present knowledge of the habits of 

 the merostome crustaceans derived both from the living and fossil 

 forms, indicates the shallow water or barachois origin of all sediments 

 in which these remains abound" (36, 302). He does not, however, 

 accept Grabau's interpretation of a torrential origin for the Shawan- 

 gunk deposits, but thinks rather that they were formed in an Appa- 

 lachian Gulf cut off from the ocean on the east by the Shawangunk 

 Mountains, the material being swept down from the land and forming 

 a delta deposit, the terrestrial waters preventing a highly saline con- 

 dition in the gulf. The eurypterids, according to this view, were 

 marine, forms caught in a gulf of not too great salinity. 



In the second volume of Chamberlin and Salisbury's Geology pub- 

 lished in 1907, the eurypterid problem s again taken up as follows: 

 ''These giants among their kind seem clearly to have been aquatic 

 forms, but whether they were primarily marine or fresh-water habi- 

 tants is not so obvious. They are wholly extinct, and their habitat 

 can only be inferred from their associations. Some crustacean frag- 

 ments that seem to belong to the same sub-class as the eurypterids 

 (Merostomata) have been found by Walcott in Pre-Cambrian beds, 

 but their associates are too few to throw much light on this question, 

 though they favor a marine habitat.'' (Walcott considers that they 

 favor non-marine conditions.) "A very few eurypterids appear in 

 the Ordovician, where they are associated with marine invertebrates. 

 In the Waterlime beds they are associated with ceratiocarids and 

 ostracods which are usually marine, and very rarely, with certain 

 brachiopods which are marine. In the transition beds of England, 

 Sweden, and Russia, the eurypterids are associated more freely with 

 marine forms, but they are also associated with the seeds of land 

 plants and with fish which in the succeeding stage, seem to have 



