THE ISLANDS OF THE BAY OF BENGAL. 213 



This group is one which varies so very greatly not only as 

 regards size of crest, but also as to size of bill according to age, 

 and the former according to season also, that an enormous series 

 from each locality is necessary before any definite conclusion in 

 regard to the specific value of the different races can be arrived 

 at. 



Now affinis of the Andamans closely resembles malabarieus, 

 except, first, in being somewhat larger (wing averaging 6'25) 

 and having a somewhat larger bill ; and second, in having a much 

 smaller crest ' T in regard to the latter it is intermediate between 

 platurus and malabarieus. On the other hand, the Nicobar bird, 

 while differing in no other particular that I can discover, 

 though perhaps the tails average somewhat shorter, have a 

 slightly longer crest than the Andaman birds, and are nearly 

 intermediate in this respect betwen affinis and malabarieus. This 

 difference between the Andaman and Nicobar birds in the length 

 of crest appears from the numerous specimens we obtained to 

 be absolutely constant ; but it is not, in my opinion, sufficient to 

 warrant the specific separation of the two. 



I met with this species, but always singly or in pairs, from 

 Galatea Bay, the southernmost point of the Nicobars up to the 

 Great Coco, the most northerly point of the Andaman group. Of 

 this species Mr. Davison says : — 



"Tolerably plentiful about the Andamans, but somewhat scarcer 

 on the Nicobars. I one evening watched several of these 

 birds in company with several Eurystomus orientalis, Dissemu- 

 roides andamanensis, Chcetnra indiea, Hirundo rustica, and a large 

 number of Collocalia linelii, hawking a very large flight of 

 ants (that appeared after a heavy shower of rain), and although 

 the swifts and swallows were "swifter' 1 '' in their flight, I think 

 the most graceful by far were the Dissemuri. I have seen and 

 shot these birds more frequently in gardens bordering the forest, 

 than I have even seen their congener in similar situations in 

 Southern India/' 



Beavan's original description of the Andaman birds has 

 already been given, (Stray Feathers, 1873, p. 67) ; but this must 

 have been taken from an immature bird, as all fully adult indi- 

 viduals have a small frontal crest, the longest feathers in which 

 are from 0*5 to 08 in length ; old males having them of course 

 longest, while the young birds, in which the lengthened external 

 tail feathers have not yet been developed, and some even in 

 which they are developed, have scarcely any perceptible elonga- 

 tion of the frontal feathers. In the finest Nicobar birds the 

 longest crest feathers are nearly an inch in length. 



