APTEEODON MACEOGNATHUS. 229 



articular surfaces being oval in outline. The dimensions (in centimetres) of this 

 vertebra are : — 



Length, from top of odontoid to posterior face of centrum . . 6-6 



Width of anterior articular surface of centrum 5 



„ posterior articular surface of centrum . ... 2-9 



Height to top of arch 67 app. 



"Width between outer ends of zygapophyses 4-7 



Left humerus of (?) Apterodon maerognathus : A, from front ; B, from outer side. 



6.^., bicipital groove; i^., deltoid crest ; «n./., entepicondylar foramen ; A., head ; i.e., inner condyle; i.<., inner 

 tuberosity ; o.c, outer condyle ; o.t., outer (greater) tuberosity ; s.r., supinator ridge. J nat. size. 



C. 9445. Left humerus (text-fig. 74). The head (h.) is strongly convex and greatly elongated from 

 before backwards ; it looks as much backwards as upwards, while from side to side it is 

 narrow and not very strongly convex. The outer tuberosity (o.i.) is high and somewhat 

 compressed, its outer face is flattened, the inner concave. The inner tuberosity [i.t.) 

 is a massive prominence with a flattened end ; between it and the outer tuberosity is 

 a deep bicipital groove (h.g.). The shaft is very strongly compressed laterally and the 



