79 



Professor Owen figures and describes (Reptiles of the Cretaceous, Palc- 

 ontographical Society) a vertel)ra whicli very closely resembles the cervical 

 6i Elasmosaurus. He considers it to be the cervical of a peculiar Plesiosau- 

 nis, which he calls 1\ constrictus, remarking, at the same time, its remark- 

 ably inferior plcurapophyses. 



Elasmosaurus platyurus, Cope. 



This, after Mosasaurus, the most elongate of the sea-sanrians yet discov- 

 ered, is represented by a more than usually complete skeleton in the museum 

 of the Academy of Natural Sciences of Phila'delphia. It was found by Dr. 

 Theophilus H. Turner, the physician of the garrison at Fort Wallace, a point 

 situated near the boundary-line between Kansas and Colorado, and a short 

 distance north from the Smoky Hill Fork of the Kansas River. Portions of 

 two vertebrae, presented by him to Dr. Leconte when on his geological tour 

 in the interest of the United States Pacific Railroad Company, were brought 

 by the latter gentleman to Philadelphia, and indicated to the writer the exist- 

 ence of an unknown plesiosauroid reptile. Subsequent correspondence with 

 Dr. Turner resulted in his employing a number of men, who engaged in exca- 

 vations, and succeeded in obtaining a large part of the monster. Its vertebrae 

 were found to be almost continuous, except a vacancy of some four feet in 

 the anterior dorsal region. They formed a curved line, a considerable part 

 of whose convexity was visible on the escarpment of a bluif of clay-shale rock, 

 with seams and crystals of gypsum. The bones were all coated with a thin 

 layer of gypsum, and, in some places, their dense layer had been destroyed by 

 conversion into sulphate of lime. 



The scapular arch was tpiind in large part adhering to the bodies and 

 neural spines of a series of the anterior dorsal vertebras, and was detached 

 from it at the academy. The pelvic arch had been slightly crushed, and the 

 lumbo-sacral vertebrae forced into contact with the ischia, where they remain. 

 A broken extremity of the sup|)osed ilium was forced into the matrix which 

 supports the ischia. Many of the dorsal and caudal vertebrae were sent, and 

 remain in continuous masses, so that the succession is readily traced, and the 

 true relations of the extremities preserved. 



In removing the matrix from beneath the vertebrae, scales and teeth of 

 some six species of Physoe/ysf and Physostomus fishes were found, including 

 an Enchodus and a Pha,sgamrfits ; the latter indicating a new species, which I 



