Page:The Habitat of the Eurypterida.djvu/26

 Northern Indiana (Schuchert 255, 467), which is in turn correlated with the Lockport of New York. The latter correlation may stand, but the former is not supported by palaeontological evidence. In a private communication from E. M. Kindle, who has written quite an extensive paper on the Stratigraphy of the Niagara of Northern Indiana (139), the following comment is made in reference to the statement that the Kokomo eurypterids are found in the Lockport-Noblesville horizon: "This reference of course is an unfortunate error and is presumably based upon a correlation of the Kokomo limestone and the Noblesville limestone of Indiana which is undoubtedly erroneous. There is practically nothing in common between the faunas of the Noblesville and the Kokomo. The lithology of the beds is quite as unlike as their faunas so that there is absolutely no ground for correlating these two distinct faunas." Since Kindle has done considerable work in the region and made extensive collections of the fossils, his statement is of importance. Palaeontologically it appears that the Kokomo is surely not earlier than Salinan and is more probably Monroan, corresponding to one of the waterlimes in New York. The eurypterid remains are very thin films, scarcely more than impressions, so that scale markings often are not visible. The preservation is not nearly so perfect as in the Bertie waterlime of New York. There are at least 40 feet of limestone, characterized by thin lamination of bedding planes and the presence of eurypterids. Above this horizon is a series of limestones, not thinly laminated, containing a rather rich brachiopod fauna, but with the eurypterids the only other fossils are ceratiocarids. The brachiopod fauna, so far as is possible to learn from the literature, occurs at a different level from that in which the merostomes are found (Foerste, 67, 6–8). Four species have been reported from the merostome beds: Eurypterus ranilarva Cl. and R., E. (Onychopterus) kokomoensis Miller and Gurley, Eusarcus newlini (Claypole) and Stylonurus (Drepanopterus) longicaudatus Cl. and R., giving altogether a fairly large fauna and one that is sufficiently well preserved for purposes of characterization.

. The Devonic of America shows a great decline of the eurypterids, so far as we can judge from the fossil record, for, while in the Siluric there had been an ever-increasing number of species and of individuals, in the Devonic, on the other hand, there are no representatives in the Lower and Middle, and it is not until the very top of the Upper that a few stragglers are found. The first, a