172 University of Kansas Geological Survey. 



over the orbit. Quadrate with a short suprastapedial process. 

 Humerus not broad, the proximal end angulated, the distal end 

 without radial process. Ulna and radius slender. A single 

 carpal or tarsal bone present, not articulating with the adjacent 

 bones. Phalanges very numerous, the fifth finger not reduced. 

 Hind limbs as large as the anterior. Spines of caudal verte- 

 brae not elongated before the distal end. Thoracic vertebrae 

 twelve to thirteen in number, the lumbo-dorsals about ten, the 

 pygal caudals five ; whole number of vertebrae not exceeding 

 120 ; no zygosphene. Coracoid not emarginate. 



The rightful name of this genus cannot be determined until 

 more is known about the forms described from incomplete ma- 

 terial from New Jersey. It is altogether likely that Nectopor- 

 theus is the same, and it is possible that Macrosaurus and 

 Lesticodus are. In this uncertainty Tyldsaurus may be retained 

 for the present. 



Macrosaurus Isevis Owen, was proposed for a genus and species 

 represented by two dorsal vertebrae from the Green sand of New 

 Jersey. Leidy (Cretaceous Reptilia, 75) referred other remains to 

 the same species, but with the remark, " I cannot avoid the sus- 

 picion that both the specimens in question and those described 

 by the high authority just mentioned [OwenJ really appertain 

 to a dorsal series of Mosasaurus." The vertebrae figured by 

 Leidy seem to resemble those Kansas forms referred to Tylo- 

 saurus, but inasmuch as the genus is distinguished with difficulty 

 by the vertebrae alone it would be hazardous to say with any 

 degree of certainty that they are really the same. Cope, in 1870 

 (Extinct Batrachia, etc.), referred certain bones to this same 

 species under the name Liodon. In the plates of the same work 

 he figured two or three vertebrae over the name of L. validus, 

 referred to L. Isevis in the text, and to Clidastes antivalidus in 

 the explanation of the plates. The different names that he 

 used are sufficient evidence of his uncertainty. 



In the Proceedings of the Boston Society of Natural History 

 for 1869, p. 260, Cope says of Macrosaurus: "This genus has 

 undoubted relationships to Clidastes; I have observed in a few 



