THE BIRDS OF NORTH CACHAR. 131 



breadth ; of course, their size renders them distinguishable from all other 

 fork-tails' eggs, except H. leschenaulti, and from these they differ a good 

 deal in colour. Most of my eggs have the markings consisting princi- 

 pally of fair-sized blotches, and, in two out of three, these are almost 

 entirely confined to the larger end. The ground is white generally- 

 tinged with green, less often with grey or greyish-yellow ; generally, 

 too, the markings are of a reddish-brown, but they also vary consider- 

 ably, ranging between clear pale rufous-red and a dark violet-brown, 

 now and then pale violet spotted eggs being met with. 



(267) H. schistaceus. — The Slaty-backed Fork-tail. 

 Oates, No. 632 ; Hume, No. 586. 

 The bird of these hills averages very small, and the following are the 

 measurements of the birds I have met with : — 



Length 8'2" to 8*6" according to the length of the tail 4'4» to 4"8" 

 (one bird measured 8*8" and had a tail almost 5") ; wing 3'3" to 3"6" ; 

 bill at front '6" and from gape *8"; tarsus '91". 



All the specimens in the Indian Museum, Calcutta, are far below 

 Oates' measurements. 



In immature birds the crown of the head is a rusty-black. My eggs 

 are like those described in Hume's ll Nests and Eggs," but are not like 

 those of H. guttatus. In most of my eggs the spots are pretty equally 

 distributed over the whole surface. 



(268) H. immaculatus. — The Black-backed Fork-tail. 

 Oates, No. 633 ; Hume, No. 585. 

 Just as common as the last bird. 



I have taken numerous nests and have found them to exactly resem- 

 ble those of H schistaceus, though the lining of skeleton leaves, so 

 invariably found in nests of that bird, are not quite so invariably found 

 in those of the present bird. 



The eggs, too, closely resemble those of H. schistaceus, but on the 

 whole they are decidedly darker, both in general colour and markings, 

 which are generally more numerous also. I have never seen a ring or 

 cap in any of these birds' eggs. 



(269) H. leschenaulti. — Leschenault's Fork-tail. 

 Oates, No. 634 ; Hume, No. 584 Ter. 

 Very rare in North Cachar and, as far as I know, entirely confined, 

 to the Laisung Eiver and the small streams which empty themselves 



