1849.] in the Asiatic Society's Museum. 809 



intact and completely separative. During the night C. affmis is equally 

 vigilant with its Malayan representative. The latter would appear to 

 be the common house Swift of the Malayan peninsula, taking the place 

 of C. affinis of India ; while C. vittatus would seem to be exclusively 

 a mountain species, which is common at Pinang, and which Capt. 

 Hutton has obtained from the Tyne range of mountains near Simla ; 

 and C. leuconyx may be the representative of the last on the mountains 

 of S. India. 



No. 420. Acanthylis leucopygialis, nobis. Size of A. sylva- 

 tica, Tickell, /. A. S. XV, 284 ; but wholly deep black with a faint 

 gloss of blue, except the upper tail-coverts which are greyish-white and 

 black-shafted : tail almost square, i. e. the barbed portion of the fea- 

 thers ; their spinous tips well developed, those of the middle feathers 

 protruding f in. Length of a male 4f in., by lOf in. in alar expanse ; 

 wing 4f in. ; and tail to end of spines If in. 



From Pinang ; where not a common species, two or three of them 

 appearing now and then about the hill on the island, their rapid flight 

 rendering them difficult to shoot like the rest of the genus. The large 

 Malayan, Nilgiri, and Ceylon species {A. gigantea) was observed on the 

 same occasion : but our informant was unable to procure a specimen 

 from the extreme velocity of its flight, which produced a loud rustling 

 or rushing sound through the air. 



Collocalia ? (No. 428, H., CataL, p. 315). Several 



specimens of a Collocalia from the Navigators' Islands differ only from 

 the Indian and Malayan C. brevirostris, (McClelland, v. nidifica, Gray), 

 in being rather blacker, with a dingy whitish band across the rump, 

 seen obscurely in some Indian specimens but not in others ; though 

 never so distinct or nearly so as in the Polynesian race. The latter is 

 much too large and too dull-coloured to correspond with Mr. G. R. 

 Gray's figure of his C. troglodytes, from the Malayan peninsula. That 

 a Collocalia inhabits the S. Seas is, we believe, not generally known ; and 

 C. francica, (Gmelin), is another true species of this well marked 

 generic form inhabiting the Mauritius, Madagascar, and probably all 

 suitable parts of the E. Coast of Africa. Some few Indian specimens of 

 C. brevirostris have the tarse more or less feathered, as in Cypselm 

 (verus) . 



5 M 



