182 MEMOIRS OF THE CARNEGIE MUSEUM 



" The posterior border of the ischium is straighter than in carbo and the iUo-pubic 

 articulation one third shorter. 



" The femur is 5 mm. longer than that of carbo, in every way much more massive, 

 and with all the muscular ridges more pronounced, while curiously enough it is 

 more pneumatic, having several foramina in the ventral aspect of the neck that are 

 lacking in carbo. 



" There is nothing to distinguish the femur of urile from one of dilophus of the 

 •same length, and of the two that of dilophus is slightly the heavier. 



" But in the specimen of urile in which the humerus corresponds in length to that 

 of dilophus, the femur and tibia are both longer and heavier than in dilophus, and 

 the tarsus a little lighter. 



" The phalanges, again, are more massive in urile than in dilophus. 



" The smallest of the three tibiae is slightly longer than that of carbo, the cnemial 

 crest is more expanded, and the cnemial ridges farther apart and more pronounced. 



" The distal extremity of the tibia is also wider than in carbo, but at its smallest 

 diameter the shaft is no larger. 



'' The muscular ridges and grooves are more marked than in carbo, but in the ab- 

 sence of more material and making due allowance for individual variation, it is dif- 

 ficult to point out characters which definitely distinguish the tibite of the two birds. 



" The tarsus is of the same length as in carbo, but much wider, and, as through- 

 out, with all the ridges more pronounced. 



" Little can be said concerning the three cervical vertebra?, except that, unlike the 

 other bones, they are less strongly built than the corresponding bones in carbo. 



" From the foregoing notes it will be seen that the differences existing between 

 corresponding bones of perspicillatus and carbo also exist between the same bones of 

 urile and dilophus, and that conversely perspicillatus and urile agree with one another 

 as do carbo and dilophus. 



" The subgenera Phalacrocorax and Urile, therefore, seem to rest on good struc- 

 tural foundations, each being characterized by internal as well as external characters. 



" Unfortunately no skullof perspicillatus is to be had, but the crania of carbo and 

 dilophus agree with one another, while differing strikingly from the cranium of 

 urile. 



" From the harmony of the other parts its not assuming too much to suppose 

 that the skull of perspicillatus would resemble that of urile.'' ^ 



"With the exception of the sternum the greater size of the bones distinguishes 

 those of perspicillatus from those of urile, while well-marked differences of shape or 

 proportion exist between the corresponding bones of perspicillatus and carbo. 



