177 



The Idcnlily wliciicr lliis reptile was first procured is near Fort McRac, 

 in New Mexico. It was discovered by Dr. W. B. Lyon, surgeon at that post, 

 and by him sent to the Army Medical Museum, at Washington, whose 

 director placed it in the collection of the Smithsonian Institution. The 

 attention to the paleontology of his neighborhood by Dr. Lyon will always 

 be cause of satisfaction to students, and his name will be remembered with 

 that of Turner (discoverer of the Elasmosaurus ])latyurus, Cope), Sternl)erg, 



and others. 



LioDON NEPJt:oLicus, Cope. 



Rhamphosaunis nepceoHcus, Cope, MS. 



Represented by the niandil)ular and parts of the maxillary and premax- 

 illary bones, the quadrate, a dorsal vertebra, etc, of a single individual. 

 These all indicate an animal related lo the large L. proriger, l)ut not more 

 ihan one-third the size or less. It is about the same size as the L. micromus, 

 Marsh, but is much more like the L. proriger in characters, so as to rcnd(!r 

 it important to ascertain whether it be not a young individual of that species. 

 An examination having convinced me that such is not the case, the points 

 of distinction will be given farther on. 



The premaxillary is very prominent, forming a rostrum, whose inferior 

 face is narrowed, and suddenly descends to a prominent transverse ridge, 

 which bounds the anterior alveoli in front. The four premaxillary teeth 

 stand on an area a little broader than long. Extremity broken. The anterior 

 suture of the maxillary is vertical and zigzag. It displays a lateral contrac- 

 tion just, behind the first tooth; while the anterior margin of the nostril is 

 above the third tooth. The teeth of both jaws have broadly oval bases, and 

 apices with two cutting-edges and lenticular section. The inner face is more 

 convex than the outer, most so in the anterior part of the jaws, and neither 

 is faceted. The enamel is finely striate-grooved, especially toward the base. 

 The mandible is light and thin, and diminishes in depth posteriorly. The 

 coronoid is small, and tlic angle is produced backward and but little down- 

 ward. Tlu! rami are not complete; the large portions preserved exhibit 

 teeth at intervals of precisely an inch. Professor Mudge, who discovered 

 the specimen, states that the jaw, when together, measured twenty-six inches 

 in length, wdiich would leave thirteen inches lor the dcntary bone. This is 

 not flir from the true number of teeth. 



The quadrate resend)les that of /.. di/spdor in various respects. The 



23 c 



