Permo-Carhoniferous Ammonoids of the Glass Mountains 217 



Plate III. 



Fig. 1-6 .. Gastrioceras altudense nov.sp. — Zone of Perrinites (Leonard form- 

 ation). — South of Bird's mine near the intrusive plug on Capt. 

 James's ranch, Altuda Mountain, near Marathon, Brewster 

 County. 



Fig. 1, side view; fig. 2, front; fig. 3, venter, of a medium-sized 

 specimen; natural size. 



Fig. 4, side view ; fig. 5, front ; fig. 6, venter, of a smaller specimen ; 

 natural size. 

 Fig. 7-8. .Gastrioceras sp. nov. indet. — Zone of Waagenoceras (Word forma- 

 tion). ^Junction of Gilliam and Road canyons. Glass Mountains. 



Fig. 7, side view; natural size 



Fig. 8, ornamentation on venter of the same specimen ; natural size. 

 Fig. 9-lG. .ScKisioceras J. P. Smithi nov. sp. — Gaptank formation, Pennsyl- 

 vanian. — Two miles south of Gap Tank, Glass Mountains. 



Fig. 9, front; fig. 10, side view; fig. 11, venter; fig. 12, external 

 suture; natural size. 



Fig. 13, front; fig. 14, side view; fig. 15, venter; fig. 16, external 

 suture; natural size. 



