162 Annals of the Carnegie Museum. 



higher and thicker posteriorly where there is a thickened heavy- 

 tubercle. The spine of the second cervical is low anteriorly and soon 

 divides into two sessile ridges which diverge and then converge, send- 

 ing backward parallel branches. The fourth and fifth cervicals resemble 

 the third in general form, but there is a quite prominent tubercle on 

 the fifth. 



The skull of Procamelus elrodi is nearly as large as that of Alticame- 

 lus altus described by Matthew, while the neck is much shorter. The 

 separate measurements of the vertebrae in Procamelus elrodi give a 

 total of 1036 mm. while that oi Alticameliis altus gives 1560 mm. 



This species is named in honor of my friend Professor Merton J. 

 Elrod who has done so much for scientific research in Montana, and 

 to whom I owe a debt of gratitude. 



Measurements of Procatnehis elrodi. 



Mm. 



Length of skull, basal 429 



" '* " including sagittal crest 503 



Width " " at canines 60 



Length " " at diastema between Pi- and P^ 48 



Width " " " posterior orbits 165 



" " " "tympanies iii 



Height" " " M^ 123 



" " " " " and including tympanic bullae 118 



" " occiput 90 



Length of mandible including incisors 380 



Depth of " at canine 19 



■*■ \ • Jo 



'< " " " p_ 40 



" " " " Mj- 50 



" " " " Mj^, posterior part 65 



Anteroposterior diameter of ascending ramus of mandible at posterior 



angle 85 



Length of upper dental series from I^ 223 



" " molar-premolar series 163 



" " premolar series 81 



" " molar series 82 



" " 13 15 



Width « " 13 



Length " space between L' and canine 19 



" " canine 15 



Width " " 14 



Length of space between canine and P^ 15 



" " pi 14 



Width of PJ 10 



