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DE. E. W. SHTJFELDT's MOEPHOLOGICAL 



in alcohol. It will be observed that the brain of Ghordeiles 

 is considerably larger than the brain of the Whip-poor-will, 

 notwithstanding the fact that in the latter bird the skull is 

 markedly wider, longer, and flatter; while in the Nighthawk the 

 ])arietal region of the skull is more dome-like and rounded. 

 The eyes in the Nighthawk are rather larger than they are 

 in the Whip-poor-will ; while in the latter the recurved limbs of 

 the liyoidean cornua are longer, more median, and reach higher 

 up on the cranium than they do in Ghordeiles. 



Marked diflferences of course characterize the skulls of these 

 two forms ; but of this we shall have something to say later : the 

 inter-ramal layer of muscles is thicker in Ghordeiles than it 

 is in Antrostomus, completely shutting out of sight the hyoidean 

 apparatus in the former bird, while its form can be easily made 

 out in the last-named type through this muscular layer. 



We need not enter here upon a comparison of the structure of 

 the neck in these two birds, but proceed at once to remove 

 the skin from the body and limbs. 



On the Mode of Insertion of the Patagial Muscles of the 

 Pectoral Limh. 



These I not only examined in the specimens before me of An- 

 trostomus and Ghordeiles texensis, but in a number of other 

 species of the latter genus, with the following results. Our 

 American Whip-poor-will, I find, has the tendons of these 

 patagial muscles of the arm inserted in precisely the same 

 manner as Grarrod found them in Gaprimulgus europceus, see 

 either in his " Collected Memoirs," or in my copy of his figure 

 in my " Contributions to the Anatomy of Geococcycc " (P. Z. S. 

 1886, p. 471). But it will be as well to mention here that 

 these tendons are far more slender than one would be led to suppose 

 from this anatomist's drawing alone. They are exceedingly 

 delicate in structure. This remark, however, does not so well 

 apply to these tendons of the patagial muscles as we find them 

 in the genus Ghordeiles ; here they are decidedly broader and 

 stronger than they are in the Whip-poor-will, and also present 

 certain well-marked diff'erences. Now, although the plan of 

 arrangement is essentially the same in the Nighthawks, we find 

 that the tendon (the main tendon) of the tensor patagii brevis is 



