BRA C HI POD A — TEL TREMA TA , 



337 



Fig. 429. Spirifer camera/us. Two individuals showing variation. 

 (Ind. Geol. Survey). 



373. S. rockymontanus Marcou. (Fig. 430.) Carbonic. 



Hinge line a trifle shorter than the width of the shell below. 

 Pedicle valve with moderately well defined 

 sinus and concave cardinal area with beak 

 strongly incurved over it. Whole surlace 

 marked by 24 to34 quite uniform plications. 



Widely distributed through North Amer- 

 ica. 



CIV. Reticulata McCoy. 



Like Spirifer but with hinge line less than 

 the greatest diameter of the shell. Radial 

 plications obsolescent or absent. Surface 

 bearing rows of fine spines placed on concen- 



. . ,,., . ~ . . ro-kymontanus. 



trie stnations or ridges. Silunc-Carbonic. Hall , 



Conspicuously spine-bearing *. 



* Small, diameter about § inch 377. R. cooperensis. 



* Of medium size, diameter exceeding 1 inch I. 



1. Width much exceeding length a. 



a. No plications on surface 378. R. pseudolineata. 



a. Low plications present (3-9 on each side the median line). 



374. R. fimbriata. 

 I. Width and length about equal 379. R. setigcra. 



