ART. 23. AN EXTINCT VARANID LIZARD GILMORE. 3 



all in a fragmentary condition, and are embedded in freslily broken pieces of 

 an ash-colored rock. Before disturbance they appear to have bs-en mostly entire 

 and preserved nearly in conjunction. They are black, and their interior is 

 occupied with crystalline calcite. 



Fragments of bones exhibit well-developed limbs, with long toes, strong ribs, 

 and a long tail, altogether indicating a form like that of ordinary living lacer- 

 tians. The long bones, even to those of the toes, are hollow. The vertebrae 

 exhibit the ball-and-socket articulation of their bodies, but only a single pair 

 of zygapophyses in front and behind. No zygantral and zygosphenal articula- 

 tion appears to have existed. 



The articular ball of the vertebi'al body is much wider than high, and is 

 directed upward, with an inclination backward. 



The body of several dorsals is quite straight inferiorly, fore and aft, and 

 measures half an inch in length. The ball is four lines wide and about half 

 as thick. The breadth at the anterior zygapophyses is eight lines, and at 

 tlie articulations for the ribs, just exterior to the latter, three-fourths of an 

 inch. 



HjTDophyses for the articulation of chevrons are situated one-fourth the 

 length of the body from the posterior extremity. 



A tooth was found, after careful search, in proximity to what appear to be 

 traces of the skull. It consisted of the crown, broken from its connection, 

 the character of which, therefore, can not be ascertained. 



The crown of the tooth is compressed conical, slightly curved inwardly and 

 backward, sharp pointed, with abruptly impressed trenchent borders; is smooth 

 and shining. It is hollow and has thick walls. The transverse section is 

 rhomboidally oval, with acute poles. The length is about li lines ; the breadth 

 three-fourths of a line ; thickness one-half a line. 



The remains would indicate an animal as large as the largest of our living 

 iguanians. 



For the generic name of the animal I would propose to use the euphonious 

 one of Saniwa which, according to Professor Hayden, is that used by one of 

 the Indian tribes of the Upper Missouri for a rock lizard. The species may 

 be named Saniwa ensidens. 



DESCRIPTION OF THK TYPE SKELETON OF SANIWA ENSIDENS, 



LEIDY. 



It will be seen from an examination of the preceding list of the 

 bones preserved of the type of /Saniwa ensidens Leidy that a very 

 considerable part of the skull and lower jaws has been preserved. 

 Most of these bones, excepting the palate shown in plate 1, were 

 found disarticulated, though none of the bones were far removed 

 from one another in the matrix. Curiously enough the larger and 

 heavier elements of the skull, such as the parietals, irontals, nasals, 

 and premaxillaries, are entirely missing. It is also unfortunate 

 that the anterior ends of the articulated maxillaries and vomers, as 

 well as the symphysial ends of the dentaries, are wanting. These 

 parts extended into another block of the matrix, which was either 

 rejected in the field or has since been lost. 



