132 Mr. P. R. Lowe on the 



femoral tract (Pt. femoralis) is strongly defined, and lias 

 the sliape of a scalene triangle. 



The humeral tract {Pt. hiimeralis) is sharply defined and 

 calls for no comment. 



The uropygium is not tufted. The orifice of the gland 

 is merely indicated by an invagination of the skin. It is 

 not prolonged in the form of a nipple. There are twelve 

 tail-feathers with twelve coverts. 



The ventral tract {Pt. ventralis) splits as nsnal (in the 

 Waders) into a median and a pectoral division (see text- 

 figure 1 B). Except that two divaricate extensions of the 

 median tract towai'ds the inguinal region may be observed, 

 it calls for no comment. 



Rhamphotheca. The curious horny sheath so characteristic 

 of the Sheath-bills is in the embryo observed to be concrete 

 with the horny substance of the bill, being only indicated 

 by a faint line of demarcation. 



Podotheca bare, reticulate. 



Claws. There is a distinctly visible claw on the pollex. 

 Those of the toes are strong, blunt, and galline in appear- 

 ance. 



Toes slightly webbed at their bases, with a lateral fringe- 

 like extension of the podotheca. 



Summary. — Pterylosis limicoline*, presenting its own 

 slight peculiarities and no gallinaceous traits. Nitzsch 

 says Chionis has exactly the pterylosis of Recwvirostra. 

 Unfortunately I have been unable to secure any embryos 

 or adults of Recwvirostra, Hcematcpus or Stercorarius with 

 which to make a comparison with the ))terylographical 

 features of Chionarchus. There are well-marked points of 

 distinction in com])arison with the pterylosis of Larus, 

 Avhich I have carefully examined. In general appearance 

 the chick of Chionarchiis is very Skua-like. The coloration 

 of the down is a uniform smutty brown with no indication 

 of pattern whatever, except that the head is lighter in 

 colour than the rest of the upper parts and the under parts 

 dirty white. 



* Usiii"- llic wtml liinicoliiic in ;i jji'o.id st-ii.-e. 



