go THE BIOLOGICAL REVIEW. 



Nos. 6 and 7 are both young males of the year. No. 7 is of 

 special interest, as it bears undoubted signs of youth. General 

 coloration same as adults, but having down very conspicuous 

 over the whole body. The head, back, under parts and thighs 

 especially, and some of the feathers of the back show this 

 feature ; the dark glossy green of pileum is somewhat obscured 

 with it. This down is about half an inch in length, and is 

 attached to the tip of the shafts of the feathers, from one to four 

 barbs being attached to one tip ; it is of a light brown color, 

 darkest on the crown. 



On the crissum, the feathers are of a very loose and downy 

 nature and of a dusky color, excepting some white in the anal 

 region. 



The measurements (from dry skin) are as follows: — wing, 

 4.20; tail, 1.45(F); middle toe, 1.45; hind toe, .70; gonys, .30; 

 nasal fossa, 1.10 ; depth of bill at middle, .26. 



It is about ten per cent, less than the adult male, No. 5, in 

 all measurements excepting those of the bill ; in No. 5 the 

 culmen and gonys are each .35 longer than in No. 7, a great 

 variation. 



No. 6 is similar to No. 7, but has only a few feathers of the 

 head with down. The back is without the green gloss, excepting 

 on the tail and edges of some of the secondaries, and is suffused 

 with chestnut, thus resembling the adult females. 



I have examined the specimen (No. 1), now in the Canadian 

 Institute, and believe it to be an adult male, as it is almost 

 identical in coloration to the adult males, Nos. 2 and 5 ; it lacks 

 any white on the lower parts, and in this respect resembles 

 No. 3. 



Ardetta neoxena differs considerably from ex His in the 

 coloration of the feet ; the former have the tarsus and upper 

 surface of the toes a dark " olive green," and the soles " orange," 

 while the latter have a light greenish-yellow tarsus and yellow 

 soles. 



The males of neoxena and exilis correspond in colour only on 

 the pileum and back, while the females of neoxena are much 

 darker on these parts than exilis. 



