Plate 12. 



Fig. 1. Sauvagesia coloradensis Stephenson. View, natural size, of the type 

 specimen on tlie side bearing tlie siplional areas (E) and (S). from the 

 upper part of the Mendez shale, Chocoy hacienda, from gullies li kilometers 

 northwest of Omaha station. The surface has been roughened and consider- 

 ably damaged by corrosion, and a small unidentified oyster is attached to 

 the shell. Cat. No. 32505, U.S.N.M. Page 11. 



Fig. 2. Diagram of a portion of the lower broken edge of the type specimen of 

 8. coloradensis, showing the ligamental ridge (L) in cross section. Page 11. 



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