40 ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 



excepting in its less size, slenderness of limbs, and less deeply forked tail ; and 

 the latter difference may perhaps be owing to youth. 



1. Hirundo Leucopygia. Licht. 



My specimens were obtained at Port Famine, in Tierra del Fuego, (February), 

 and at Valparaiso, in Chile, {August to September). At Port Famine they build in 

 holes in a cliff of earth. Mr. Gould says, " were it not for the bare legs of this 

 little Martin, I shovdd have some difficulty in discriminating between it and the 

 one so well known as a summer visitor in our island." 



2. Hirundo frontalis. Gould. 



H. vertice, plumis auricularibus, dor so et lunula pectorali nitide cceruleo viridescentibus, 

 nota alba supra nares, guld corporeque subtus albicantibus, crisso niveo, alis caudd- 

 quefuscis viridi tinctis, rostro nigro, pedibus intense fuscis. 



Long. tot. 4f unc. alw, 4f ; caudm, 2 ; tarsi, ^. 



Upper surface, with a greenish blue metallic gloss; which can faintly be perceived 

 on the primaries and on the tail feathers. The short feathers over each 

 nostril white, thus forming two small white marks ; those over the ridge of 

 bill pale brown, giving together the appearance of a narrow white band over 

 the upper mandible. Entire under surface and lining of wings pure white. 

 Tarsi rather darker than in H. leucopygia. 



Very slightly larger than H. leucopygia ; upper mandible rather broader. 



Inches. 



Total length 4| 



Wings . . • 4f 



Inches. 



Tail 2 



Tarsi ? 



Habitat, Monte Video, (November). 



Mr. Gould says, " this species is closely allied both to the common martin, 

 and to the last species ; from the former bird, however, its bare legs at once dis- 

 tinguish it, while it differs from the latter in being rather larger in size, in having 

 an obscure white mark on the forehead, at the base of the bill, and in having 

 the metallic lustre of the upper surface deep steel green, instead of purple, which 

 is the prevailing colour of both Hirundo leucopygia and H. urbica." 



It is abundant on the northern bank of the Plata, and more common than the 

 H. purpurea, which frequents the same localities. It probably replaces on the 

 eastern side of the continent, the H. leucopygia of Chile. 



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