352 



DR. E. W. SHUFELDt's MORPHOLOaiCAL 



the Caprimulgi are nearer the Owls, and only remotely approacli 

 the Trogons. 



Again, I can hardly agree with Mr. Beddard *, who would retain 

 such forms as Antrostomus and Chordeiles in the same " sub- 

 family ;" for surely all the essential structural characters of these 

 two forms are oi family and not subfamily rank : a comparison of 

 the skulls alone is almost sufiBcient to determine this point. And 

 the breach between Chordeiles and Steatornis must indeed be 

 wider than a mere subfamily line can indicate. 



Anatomy of the Noeth-Ameeican Hieundinid^. 



From my list of material at the beginniDg of this memoir it 

 will be seen that I have at hand specimens of every genus and 

 species of Swallow at present entitled to a place in the United - 

 States avifauna^ and a sufficient series of each to enable me to 

 fully investigate their structure. 



I will take them up, species by species, in the order in which 

 they occur in the ' Check-List ' of the American Ornithologists' 

 Union, but need not present a synoptical table of their ex- 

 ternal characters, for these are well known to ornithologists 

 and ornithotomists the world over. 



To commence with them, then, we will take a look at the ptery- 

 losis of a specimen of Progne suhis, compare it with the figures 

 given in my Plate of Ampelis cedrorum, and with Nitzsch's 

 drawing of the pterylosis of Ilirundo urhica in his ' Pterylo- 

 graphy,' and next with other American Sirundinidce. 



Now it will be remembered that we found the pterylosis of 

 Ampelis to agree essentially with most true Passeres, wherein, 

 upon the dor&^al aspect of the body, the chief feature is that the 

 " spinal tract " terminates in a lozenge-shaped pteryla situate 

 mesially between the thighs ; and on the ventral aspect we have 

 another well-known distribution of the pterylse characteristic of 

 most Passerine birds. Progne differs from all this, and agrees 

 in the main with Ilirundo urhica as figured by Nitzsch. 



This author, however, does not present in his work a ventral 

 view of the pterylosis of a Swallow, but says in his text that 

 *' the single genus Ilirundo, which constitutes this group [Hirim- 

 dines\ differs more than any other in its habitus from the 

 general type of the Singing-birds, and in this respect aj)proaches 

 P. Z. S. 1886, p. 153. 



