194 Dr. C W. Andrews — Upper Cretaceous Birds. 



on to the anterior face of the shaft as a strongly marked linea aspera, 

 which runs downwards and obliquely across towards the inner 

 distal condjde ; its full extent cannot be seen on account of the 

 incompleteness of the distal end of the specimen. This ridge 

 probably marks tlie line of insertion of the femoro-tibial muscles. 

 The outer face of the trochanter is concave, owing to the presence of 

 deep pits for the insertion of muscles, probably the ghitetis ynedius 

 and the gluteus externus. The surface truncating the posterior angle 

 of the trochanter and probably serving for the attachment of the 

 obturator muscles has already been referred to. 



Beneath the trochanteric region the bone narrows to a shaft which 

 is oval in section, the transverse diameter being a little the greater. 

 The muscular ridge on the anterior face has already been referred to, 

 and there is another strong linea aspera {I. a.) on the hinder face, 

 beginning just beneath the trochanter and running downwards and 

 outwards, apparently towards the outer condyle, and becoming very 

 strongly marked at its lower end. There is some evidence that 

 towards its lower end the shaft curved considerably backwards. 



Fig. 1. Upper end of left femur of Elopteryx 7iopcsai, gen. et sp. nov. 

 A, from behind; B, from the front; C, from above. Type-specimen, 

 fi nat. size. h. head of femur ; I. a. linea aspera ; I.t. pit for the insertion 

 of the ligamentum teres ; o.in. point of insertion of the obturator muscles ; 

 tr. trochanter. 



In the uncrushed specimen the fractured end shows that the wall 

 of the shaft consists of a hard compact outer layer measuring from 

 3'5 mm. in thickness at the front and back to about 6*5 mm. at the sides. 

 Within this there is a spongy layer of indefinite thickness enclosing 

 a central cavity. Judging so far as is possible from the crushed 

 specimen, the central cavity is larger towards the lower end of the 

 shaft, the spongj' layer being less developed, while the outer hard 

 layer also is thinner. The outer surface of the bone is sculptured 

 in a remarkable way, being raised into a series of fine wrinkles which 

 are for the most part irregular and run into one another, though in 

 some places, as for instance on parts of the anterior face of the 

 trochanter, they may be more or less parallel, and in that case, as 

 a rule, they run more or less in the direction of the long axis of the 



