104 Shu¥el.dt, Osieology of Harris's Cormorant. [,^, 



Emu 



and general reduction in calibre, much slenderer, and this has 

 given prominence to the muscular line passing down its anterior 

 aspect, especially at the lower part of its course. 



The U.S. National Museum specimens do not support all that 

 Dr. Gadow says of the coracoid of N annopterum in his above- 

 cited paper {loc. cit., p. 172), for he states, in regard to this bone, 

 that "The coracoids are much reduced in length and strength. 

 Their feet have remained as broad as they were originally, but 

 they have crept asunder to the extent of 18 mm., and the shafts 

 have been diminished at their median sides." That they have 

 become reduced in "strength" there can be no doubt, and, 

 perhaps to a slight degree, in " length," while it would not appear 

 that their " feet " have remained as broad as they were originally, 

 although the anterior and posterior facets on them, for the 

 coracoidal grooves of the sternum, have increased in depth. 



In support of this, I would invite attention to the coracoid of 

 an adult specimen of P. urile (No. 18,982). It was about as big 

 a bird as was the Harris's Cormorant numbered 19,628 of the 

 collections of the U.S. National Museum. Now, in that specimen 

 of P. urile the full width of the foot of the coracoid — or that part 

 of the sternal end of the bone which articulates with the coracoidal 

 groove of the sternum — from angle to angle measures 24 mm., 

 the same distance on the coracoid of the Harris's Cormorant 

 measuring but 18 mm. The length of this coracoid of P. urile 

 equals 72 mm., while in the specimen of Harris's it is but 58 mm. 

 long. That the reduction in the calibre of the shaft did not take 

 place exclusively on its " median side," as Dr. Gadow states, is 

 evidenced in the coracoids of the skeletons at hand. I am com- 

 pelled to believe that there was a general reduction of the bone, 

 for the reason that in all Cormorants, including our P. urile, the 

 process at the infero-external angle of the coracoid is very in- 

 conspicuous, while in Nannopternm it may attain a length of not 

 less than nine millimeters. It has, beyond doubt, acquired this 

 length by remaining almost its original size, while the shaft of 

 the bone, on its own side, has shrunk away from it in the course 

 of the diminution of its calibre as a whole. That this was the 

 case is clearly evidenced in all the coracoids of this Cormorant 

 now before me — that is, five pairs of them. 



Everyone will agree with Dr. Gadow in his statement that 

 "the reduction of the scapulae is extreme" in N annopterum 

 harrisi {loc. cit., p. 172), for not only has the head of the bone 

 suffered much reduction, but likewise in the length of its shaft, 

 the width or calibre of it not having changed to any appreciable 

 degree. This is very clearly shown in figs. 9 and 11 of Plate XVI. 

 of the present paper, where such excellent representations of these 

 bones are given that any further description of them becomes 

 quite unnecessary. 



When articulated, as in life, the scapulo-coracoidal angle equals 

 about 90° in N annopterum harrisi, whereas in ordinary Cor- 

 morants this angle ranges between 63° and 70°. Again, when 



