1901.] 



PTEKYLOSIS or THE GIANT IIUMMING-BIED. 



321 



successively shortei', the outermost having only about five feathers. 

 The median coverts each bear two tiny plumes at the base. There 

 are several rows (about five) of marginal feathers which curve 

 round on the shoulder to join the strong humeral patch. On the 

 ventral side of the wing there is a complete series of major coverts, 

 including an aquintocubital covert, and there is also an equally 

 complete series of median coverts. There is one row of minor 

 coverts together with a few others on the arm, not very regularly 

 disposed. 



Test-fig. 82. 



Hui^'Tf!. 



<^ y.-^^ ^-^^ 



Wing of Caprimulgus macrurus, dorsal view. 

 c.r.s carpal remex, with its major covert. 



The variations in the pterylosis of the wing are too numerous 

 and too little known to justify us in drawing much from a close 

 comparison of these types. They all three possess wings of com- 

 paratively simple structure, that of the Humming-bird being the 

 most so, that of the Goatsucker the least. The wing of the Goat- 

 sucker is aquintocubital, with the apparently interstitial coverts 

 present both above and below ; in the Humming-bird we see one 

 only on the dorsal side ; in Collocalia there is no sign of either. 

 The median coverts of the primaries on the dorsal side are 

 interrupted alike in the Goatsucker and the Swift; in both of 

 these birds, and especially the latter, the minor coverts of the 

 cubitus and the patagial feathers are much more numerous than 

 in the Hummins-bird. 



The Pterylosis oe the best op the Body. 



In Patagona the general feathering of the back of the head, 

 formed by the convergence of the bands above described, and 

 supplemented by additional feathers on the occiput between the 

 hyoid cornua, divides at the nape of the neck to run down on 

 each side of a great posterior cervical apterion, fully an inch long, 

 and occupying all the back of the neck nearly to the shoulders. 



The middle of the back is occupied from the shoulders to a little 

 way in front of the oil-gland by a somewhat broad, lanceolate, 

 dorsal apterion. The rest of the back is covered by a broad 

 dorsal feather-area, which in front divides into two very narrow 

 feathered strips that border the posterior cervical apterion, and 

 merge halfway up the neck with the lateral cervical feather-tracts. 



