LACERTILIA. 773 



Peltosaurus granulosus Cope. 



Paleontological Bulletin No. 15, p. 5, August 20, 1873. Annual Beport U. S. Geol. Surv. Terrs., 1873 



(1874), p. 513. 



Plate LX, figs. 1-11. 



I took numerous parts of the skeleton of an individual of this species 

 from the White River chalk-bed on Cedar Creek, in Northeastern Colorado, 

 during my expedition of 1873. The cranial fragments include the premax- 

 illary and jjarts of both maxillary bones ; the malar of one side ; the coos- 

 sified frontals and parietals sejiarated from each other. Also the greater 

 part of both mandibular rami. There are several vertebras, and many 

 dermal scuta. 



The parietal is a wide element, and has a nearly plane superior surface. 

 The granular sculpture vanishes posteriorly, leaving a wide, smooth band at 

 "the posterior border of the bone. The scutal arese are rather narrow, each 

 one longer than wide, and occupying just half of the length of the granular 

 portion of the surface. The frontal suture is perfectly straight. The frontal 

 l)one is longer than Avide, and is slightly convex in both directions. The 

 greater part of it is preserved, and displays no dermal scuta, hence the frontal 

 al scutum was large and undivided. The lateral olfactory ridges are mas- 

 sive and not very deep, being much thicker than in Exostinus serratus, and 

 are strongly beveled on the external side ; that is, to the supraorbital border. 

 The malar and postorbital bones together form a rather slender arc of a 

 circle, indicating a large orbit. The premaxillary bone has a wide, flat spine, 

 ■which is so strongly inclined as to be nearly horizontal. No portion of it 

 protrudes beyond the alveolar border, which supports seven teeth. There 

 is a foramen at the base of the spine on each side. The external surface of 

 the premaxillary is entirely smooth. On the external face of the maxillary 

 the usual foramina occur at the usual intervals. In the mandible the post- 

 dentary parts are extended, about equaling the dentary (the angle is bro- 

 ken from both rami), and are robust. The anterior fourth of the meckelian 

 groove is exposed. The external face of the dentary is convex, and is 

 pierced by five foramina, all in the anterior half. The superior aspect of the 

 surangular region is truncate or flattened, with angles separating it from the 

 lateral faces, as in other Gerrhonotidce. 



