Williston — New Genera of Permian Reptiles. 575 



Art. XL. — New Genera of Permian Reptiles ; by S. W. 



Williston. 



Among the new genera of Permian vertebrates represented 

 by material in the collections of Yale and Chicago Universi- 

 ties there are two presenting such peculiar characters as to 

 justify their present description. A third new genus of rep- 

 tiles from New Mexico is represented by parts of two skulls 

 and will be described later. Two distinctive genera of small 

 amphibians from New Mexico, of new and peculiar types, are 

 also represented in the Chicago collections by skull and limb 

 bones. 



Glaucosaurus megalops, gen. sp. no v. 



The type and only known specimen of the present genus 

 and species is an incomplete skull of small size discovered by 

 Mr. Paul Miller on Mitchell Creek, Texas, in the same horizon 

 as that of the type of Broiliellus, that is, from the lower part 

 of the Texas beds. The same horizon has also yielded five 

 specimens of Pantylus, numerous specimens of different 

 species of Captor hinus, Theropleura, etc., none of which has 

 ever been detected in the uppermost deposits. 



The skull (fig. 1) had been fossilized complete, but, when 

 found, the lower posterior part and much of the roof of the 

 occipital and parietal region were gone. Enough remains, how- 

 ever, to indicate approximately the contour of the quadrate 

 region. 



The skull is remarkably narrow and high, reminding one of 

 the general shape of the chameleons. It has a high, thin, 

 nose-like face, very much like that of Edaphosaurus, with the 

 external nares near the pointed end, and separated by a narrow 

 bar of bone. There are two teeth on each premaxilla, of small 

 size, and fifteen on each maxilla, the latter increasing a little 

 in size as far as the twelfth ; the last two are smaller. Some 

 of the teeth have been injured on the outer side in preparation, 

 showing a hollow cavity, but their outlines are visible in nearly 

 all. They are rather obtusely rounded at the extremity, the 

 front ones more acute. They appear to be acrodont, but are, 

 in all probability, protothecodont. They are not cuspidate. 



The most peculiar character of the skull, one that dis- 

 tinguished it from the skulls of other known genera, is the 

 relatively enormous size of the orbits, their greater diameter 

 being nearly equal to one-half the whole length of the skull, 

 and considerably more than the length of the face in front of 

 them. In life they looked nearly directly outward, with a 



