THE ISLANDS OF THE BAY OF BENGAL. 259 



sexes, as some females are larger than many, though not larger 

 than all the males : — 



Length, 11/5 to 13'5 ; expanse, 20 to 22 ; wing, 6*5 to 

 7-12 ; tail, from vent, 3'5 to 4-4 ; tarsus, 082 to 1-0 ; bill, 

 from gape, 1/0 to 1*15 ; bill, at front, 0'74 to 0"85 ; weight, 

 7 to 10 ozs. 



The legs and feet are pm*plish pink ; the claws plumbeous, 

 tinged pinky ; the bill is pale leaden blue, almost white at tip, 

 darker and tinged greenish quite at the base ; the irides have 

 three rings. The first pale, the second darker blue, and the third 

 pinkish buff; the lores, a line over the eye, the ear-coverts, cheeks, 

 chin, throat, neck all round, upper back, breast and upper abdomen, 

 a dull, slightly yellowish, green, yellower on the throat, greyer 

 on the back ; the forehead, crown and occiput, very delicate 

 French grey, slightly purer and paler as a rule on the forehead, 

 but occasionally tinged greenish there. Middle of back, scapulars, 

 tertiary coverts, and some of the lesser coverts of the hinder 

 secondaries, maroon. The rest of the lesser coverts, (except 

 just at the carpal joint where they are dark grey, tinged 

 greenish) darker green. Quills and secondary and primary 

 greater and median coverts, greyish black. Primaries conspicu- 

 ously though narrowly margined on their outer webs with 

 white or in some specimens pale yellow ; secondaries, and 

 their greater and median coverts, with bright yellow ; the 

 hinder ones of each very broadly so margined. In the Nicobar 

 birds the margins to the earlier secondaries are narrower than 

 in those from the Andamans, and they are often white, or pale 

 yellow instead of the bright yellow of the Andaman birds. 

 The lower back, rump, and upper tail coverts bright yellowish 

 green ; central tail feathers entirely suffused on both webs with 

 this color. The rest of the tail feathers, with broad French grey 

 tippings, below these black, but more or less suffused along the 

 tips and at the margins, and on the whole outer webs towards 

 their bases, with the same color as the central tail feathers. 

 The vent, flanks, and lower tail coverts mingled dull green 

 and pale yellow, the basal portion of the feathers being of 

 the former color, and the tips and often the margins of the latter 

 color. The whole under-surface of the wings, the axillaries, 

 and part of the sides, vary from dark slatey grey to moderately 

 dark French grey. On the lower surface of the tail all the 

 feathers are blackish for the basal two-thirds and greyish white 

 on the terminal one-third. In fine well plumaged specimens 

 the lower tail coverts reach to within about 0"8 of the end of 

 the tail. The second quill is the longest, the third nearly equal, 



