Mr. 0. Salvin on the Genus Leucopternis. 241 



The single specimen from which the above description was 

 taken was contained in a collection of bird-skins recently received 

 by Mr. E. T. Higgins from Ecuador, and was probably obtained 

 in one of the valleys of the Andes in the vicinity of Quito; but 

 on this point I can give no exact details. I at first took it to be 

 a skin of L. schistacea ; but a comparison with specimens of 

 that species at once showed the differences pointed out above. 

 Its resemblance to L. semiplumbea led me to the conclusion that 

 the former bird would find a more natural position in this genus, 

 and moreover that its removal from Urubitinga would relieve 

 that genus of an abnormal element. 



The diff'erences between Leucopternis and Urubitinga are not 

 very trenchant. They consist chiefly in the shorter tarso-meta- 

 tarsus of the former and in the proportionally longer toes; the 

 nostril is almost circular in both genera. The primaries project 

 beyond the secondaries rather further in Leucopternis than in 

 Urubitinga, the secondaries being very long in the latter genus. 

 Another distinction, which, howevei', is of a negative character, 

 is also important. In Leucopternis we have no evidence to show 

 that any of the species passes through a distinctive immature dress 

 before assuming the plumage of the adult. The immature stages 

 of the young of Urubitinga are well known ; and birds of the two 

 commonly known species in their first fawn-coloured dress 

 spotted with black are almost as familiar as adult specimens. 



Leucopternis is also closely allied to Buteo ; and the members 

 of the two genera resemble each other in habits. In Buteo, how- 

 ever, the wings are longer and more pointed, and the secondaries 

 shorter than in Leucopternis. The nostril, too, of the former 

 genus is more elliptical in shape, and thus differs from the circular 

 nasal opening of the latter. 



Since our article was written in 'Exotic Ornithology' I have 

 obtained a second specimen of Leucopternis princeps from Costa 

 Rica ; and as the skin is marked as that of a male, I take this 

 opportunity of giving its dimensions. Long, tota 3J "O, alse 14'0, 

 caudse 7*5, tarsi 3*5, dig. med. cum ungue, 2*75, rostri a rictu 

 2*2. Comparing these dimensions with those given by Mr. 

 Sclater in the ' Proceedings of the Zoological Society ' for 1865, 

 p. 429, it will be seen that they indicate a rather smaller bird 



SEK. III. VOL. II. T 



