Tlate ]]. 



Fig. 1. Sauvagcsia helti Stephenson, Exterior view, natural size, of the type, a 

 fragment from the lower part of the Mendez shale, Chocoy hacienda, from 

 gullies west of the track of the National Railways of Mexico, IJ kilometers 

 northwest of Chocoy station. State of Tamaulipas, Mexico. The part of the 

 surface shown is back of the posterior siponal area. Cat. No. 32504, 

 U.S.N.M. Page 10. 



Fig. 2. Interior view of the specimen shown in figure 1, showing especially the 

 imperfectly preserved ligamental ridge (L). Page 10. 

 24 



