On the Osteology of Nvctosaurus. 147 



measurements. 



mm. 

 Length — 211 



Width proximal extremity - - 17, 18 



Width at proximal third _- 9, 10 



Width at distal third 8, 9 



Width of distal end — 9, 10 



The third phalange has the proximal extremity preserved, com- 

 pressed from above. The surface seems to have been only slightly con- 

 ' cave. This phalange, like the preceding one, seems to have been pro- 

 portionally more slender than in Pteratiodon. 



PELVIC GIRDLE AND EXTREMITY. 



Pelvis. PI. XLI, Fig. 1. The pelvis lies with the bones nearly in 

 position, the sacrum with its ventral surface uppermost, the innominate 

 bones separated at their sutures and in juxtaposition with the sacrum, the 

 visceral surface also uppermost. 



There was in the sacrum (PI. XLI, Fig. 1, s) in life evidently a 

 considerable concavity transversely, and possibly a slight concavity longi- 

 tudinally. It is composed of six firmly united vertebra?, the sutural lines 

 between the centra clearly distinguishable. The vertebrae decrease in 

 length from the first to the fifth; the sixth is slightly longer than its 

 predecessor. The centra are flattened in the preserved specimen, though 

 possibly in life they may have been slightly convex transversely. The 

 sacral ribs show no indications of sutural connections anywhere, and are 

 broadly united distally. Between them the oval foramina decrease rapidly 

 in size, and slightly approach the middle line, the last, that between the 

 fifth and sixth vertebrae, being almost punctiform, while the first is of 

 considerable size. 



Trie first process is broad, with a broad, oblique surface, terminating 

 distally in a free, rounded margin. The pelvic brim is indicated by an 

 angular line passing outward and downward obliquely to the upper 

 border of the articular surface for the innominate bone. This surface is 

 oval, and encroaches obliquely on the front surface of the sacrum; beyond 

 it the thin margin of the sacrum does not present a sutural surface on the 

 ventral side. The lateral margins approach each other until at the hind 

 border the distance between them is less than half that at the brim of 

 the pelvis. 



The ilium (PI. XLI, Fig. 1, il) has a long, flattened or somewhat pris- 

 matic anterior process, reaching as far forward as the second presacral 

 vertebra. The process is apparently curved somewhat backward in life, 

 and also outward; it has an obtuse anterior extremity. Posteriorly the 



