Per mo -Carboniferous Ammonoids of the Glass Mountains 165 



The saddles of the suture are much shorter and stouter, although 

 the general arrangement of the suture is the same. The small speci- 

 mens of this species, like that figured by White in his pi. i, fig. 4 and 5, 

 are extremely similar to specimens of the same size of our species. 



Perrinites compressus n. sp. is also a species which is very similar 

 to P. vidriensis but its involution is more than one half of the height 

 of a whorl and its umbilicus is wider than that of the latter species; 

 the saddles of the suture are somewhat higher and less deeply seal- 

 toped. 



There exists probably another species similar to P. vidriensis. Some 

 specimens were collected by Udden^ about 2^/^ miles N 20° E of the 

 old oil derrick on Wedin's ranch on the top of the first ridge, and 

 others were brought by Mr. Chas. L. Baker and myself from the first 

 ridge northwest of Iron Mountain. Unfortunately, the specimens arc 

 too badly preserved and too small for a description. They seem to 

 belong to a species the cross-section of which is similar to that of P. 

 Cumminsi, while the umbilicus is extremely narrow. This species 

 occurs in the lower part of the Leonard formation and may possibly 

 allow a subdivision of that horizon. 



Age: 



Leonard formation, Permo-Carboniferous. 



Number of specimens examined: 

 More than a hundred. 



Locdlity: 



Two miles west-northwest of Iron Mountain, at the base of a large 

 clay sHde (very frequent); lYi miles west-northwest of Iron Moun- 

 tain (frequent) ; 3 miles north of the old oil derrick on Wedin's ranch; 

 valley north of Leonard Mountain (all these localities are in the Glass 

 Monntains) ; three miles south of Bird's mine north of intrusive plug 

 of Capt. James's ranch (very frequent) ; region of the Altuda Moun- 

 tain in the Mt. Ord range. 



'Through an error this was cited by Udden (Univ. Texas Bull. 1753, p. 13) under the 

 name 6f Waoffenoceras. 



