TACHTCINETA. 235 



Supra chalybeo-viridBscens, alis caudaque nigricantibus, illis intus tenuissime albo tenninatis; subtus albus; 

 rostro nigro, pedibus corylinis. Long, tota 57, alse 57, oaud® rectr. med. 2-0, recfcr. lat. 2-4, rostri a 

 rictu 0-6, tarsi 0-45. (Descr. maris ex Duefias, Guatemala. Mus. nostr.) 



Edb. NoETH Amekica from Alaska and Great Slave Lake to Arizona &cc.^\ Bermuda 4. 

 —Mexico {Deppe i^), Matamoras {Couch 2 3), Mazatlan {Grayson lo), Plateau of 

 Mexico [Sumichrast^, le Strange), San Jose {SaUS% Jalapa {de Oca''), Orizaba 

 {Sumichrast^ Pine ridge above Mirador {Sarforius ^) ; Guatemala {Skinner^), 

 Vera Paz 3, Duenas, Pajal Grande, San Geronimo {0. S. & F. B. G.). — Cuba. 



This species appears to be commoner in the eastern than in the western States, 

 though found over nearly the whole of North America during the breeding-season : 

 during the winter, however, large numbers remain in Florida ; others pass to Cuba, 

 Mexico, and Guatemala. 



There is no positive evidence of the species breeding in Mexico, though it is included 

 by Prof. Sumichrast amongst the resident birds of the Plateau of Mexico, and a speci- 

 men was obtained by Dr. Sartorius in the pine-region above Mirador, in the month 

 of June ^. 



In Guatemala it is a winter visitant to the tablelands and to the neighbourhood of 

 San Geronimo in Vera Paz, where it is frequently found associating with T. thalassinus. 



The habit of this species to congregate in vast flocks has often been alluded to by 

 writers on North-American ornithology ^^. We once observed a flock of this kind in 

 the open space in the forests of the Volcan de Fuego called Pajal Grande, the elevation 

 of which is about 5000 feet above the sea-level. This was on the 25th December 1873, 

 when a vast flock of these birds were seen circling round and round in a compact mass, and 

 every now and then settling on some low shrubs, weighing down the outer boughs and 

 crowding together like a swarm of bees. We could detect no object in this assemblage ; 

 it was neither the season of migration, nor was it the roosting-time, as it took place in 

 the afternoon of a bright sunny day. 



In Cuba, Dr. Gundlach includes T. bicolor amongst the regular winter visitants to 

 the island, where it arrives later than Eirimdo erythrogaster, remains the wmter, and 

 leaves again for the north in April. 



It breeds in holes in trees and in stumps, making a nest of fine soft hay, thickly 

 lined with feathers. The eggs are, like those of T. thalassinus, white ^^. 



3, Tachycineta albilinea. {Hiru7ido alUUnea, Tab. XV. fig. 1.) 



Petrochelidon albilinea, Lawr. Ann. Lye. N. Y. viii. p. 3 ' ; Scl. & Salr. P. Z. S. 1864, p. 347'. 



Tachycineta albilinea, Lawr. Mem. Bost. Soc. N. H. ii. p. 371 ^ 



Hirundo albilinea, Baird, Rev. Am. B. i. p. 300 * ; Zeledon, Cat. Av. Costa Rica, p. 5 '. 



Petrochelidon leucoptera, Lawr. Ann. Lye. N. Y. vii. p. 317 ° (nee Gm.). 



Petrochelidon littorea, Salv. P. Z. S. 1863, p. 189'; Ibis, 1866, p. 1931 



30* 



