Peterson: Tpie Osteology of Promerycochcerus. 205 



No. 1230 

 (Type) 

 Mm. 

 P- antero-posterior diameter 14 



P- transverse diameter 12 



P- antero-posterior diameter 15 



P- transverse diameter 15 



P- antero-posterior diameter 13 



P- transverse diameter 19 



M- antero-posterior diameter 27 



M- transverse diameter 26 



M- antero-posterior diameter 35 



M- transverse diameter 28 



Inferior dentition, total length 175 



Ittferior dentition, length from incisors to Mj- 90 



Molar series, length 87 



Px antero-posterior diameter 17 



Py transverse diameter 13 



P2 antero-posterior diameter 14 



Po transverse diameter 8 



P3 antero-posterior diameter 15 



P3 transverse diameter 12 



P^- antero-posterior diameter 19 



P4 transverse diameter 15 



Mx antero-posterior diameter 20 



Mx transverse diameter 17 



M5 antero-posterior diameter 27 



Mo transverse diameter 21 



M3 antero-posterior diameter 43 



M 3 transverse diameter 22 



THE VERTEBRAL COLUMN. 



Unfortunately the atlas and axis are not represented in our material. 

 The fourth, fifth, and seventh cervicals are at hand. Their neural 

 spines are quite prominent, the centra are short, vertically compressed, 

 and have a strong inferior keel. The transverse processes are shaped 

 as in P. carrikeri. 



A dorsal vertebra belonging to the type pertains to the anterior part 

 of the column and shows the usual characters found in P. carrikeri, 

 viz., a depressed centrum, deeply excavated for the heads of the ribs, 

 keeled below, with heavy transverse processes and indications that the 

 neural spine was robust. A vertebra, representing the middle of the 

 dorsal series is quite similar to corresponding bones in P. carrikeri, 

 though lighter, while the last dorsal (the fourteenth), has the neural 

 spine inclined backward, the centrum with a smaller vertical diameter, 

 and the inferior keel very much less developed. 



