STUDIES OP THE MACROCHIEES. 



355 



is pretty well known, it will not be necessary for me to enlarge 

 further upon my account of it. 



But the principal thing to be borne in mind in the present 

 connection is, that Swallows, Swifts, and Humming-birds all 

 depart from the more typical pattern of pterylosis found in 

 true Passeres. And in the case of the Swallows and Swifts, so 

 far as Nitzsch's figures and descriptions go, for I have not- yet 

 examined the Cypseli myself for this character, the pterylosis of 

 the latter is of such a pattern that it requires but very little 

 modification to make it agree with the pterylosis of a Swallow. 

 Indeed, in those Swallows where the " saddle-pteryla " of the 

 dorsum joins its bifurcations with the anterier end of the " rump- 

 band," the pattern is nearly the same, differing principally in 

 relation, width of the tracts, and position of the bifurcation of 

 the saddle, which, in Cypselus apus, is between the shoulders. 



On tlie Mode of Insertion of the Patagial Muscles 

 in the Swallotvs. 



Scarcely any difference is apparent among the various species 

 of Swallows at hand in regard to the mode of insertion of 

 this group of patagial muscles, now known to be of so important 

 a character in the taxonomy of the class. I have carefully ex- 

 amined them in all the American species, and find that, so 

 far as the tensor fatagii hrevis is concerned, both its origin and 

 insertion seem to be almost typically Passerine. This observa- 

 tion applies with equal truth to the tensor patagii Jongiis-, and as 

 these muscles are now so well known to all working morpholo- 

 gists, I need not redescribe them here ; moreover, in figure 2 

 of Plate XVII., I have drawn them for Ampelis, which will 

 recall their appearance for the Passeres. 



During the course of my dissections upon this region in the 

 HirundinidcB, however, I came across, as I did in Ampelis, what 

 I am inclined to believe is a hitherto undescribed muscle, at 

 least so far as G-arrod's descriptions go. It first came to my 

 notice in a specimen of Progne suhis, whereupon I at once dis- 

 sected a number of other individuals of the same species, and 

 found it equally well developed in all of them. 



This muscle, in part, is a dermal muscle, and arises from the 

 integuments on the anterior aspect of the neck at about its lower 



