221 



This genus was established by Professor Agassiz on a jaw-fragment from 

 Sussex, England, with a brief description. The Kansas remains resemble 

 this fragment in their corresponding parts, and I refer them to the same 

 genus for the present. 



The genus Conosaurus, Gribbes, from South Carolina, is perhaps allied 

 to this one. Its dentition is fully described by Leidy, who changes the name 

 to Conosaurops, mainly on account of the inappropriateness of the Greek 

 oavpos to a fish. This word was, however, employed by the ancients to 

 designate a fish; and the only use made of the word, out of composition, by 

 modern zoologists, is for species of that class, so that it does not seem im- 

 proper to use it here. 



Three, perhaps four, species left their remains in the strata examined by 

 the expedition. 



Pactiyehizodus caninus, Cope. 



Established on portions of perhaps two individuals, which embrace one 

 nearly complete maxillary bone ; two premaxillaries of opposite sides ; two 

 nearly perfect rami of the mandible, with numerous other portions in a frag- 

 mentary condition. 



These indicate a cranium of about a foot in length by six and a half inches 

 in width, oval in outline, with moderately obtuse muzzle. The mandibular 

 teeth are directed somewhat outward. The premaxillary is horizontal in 

 front, and the maxillary narrow. From these facts, I derive, that the head 

 was probably depressed, as in the modern Sauri, and very different from the 

 prevalent compressed form of the Porthei and allies. 



The premaxillary is several times longer than wide ; posteriorly, it is a 

 subvertical plate ; anteriorly, it terminates a narrow obtuse portion. Just 

 behind this portion, it is enlarged on the inner side, forming a knob whose 

 upper surface supports the articulation with the ethmoid. It supports the 

 two large teeth below on a common elevation of the jaw. The outer margin 

 of the bone supports ten subequal teeth, which arc one-third smaller than 

 the posterior pair. The outer alveolar ridge is a little more elevated than 

 the inner, though a little less so than on other bones which support teeth. 

 The external face of the bone is nearly smooth, and the inner unites with the 

 maxillary by striate scpiamosal suture. 



