174 



Ge^-us LEUCOPTERXIS, Kaup. 



Bcedalion Vigors, 1824 (not of Sarigny, 1809). [_Fide G. E. Gray.] 

 Leucopternis Kaup, Isis, 1847, 210. Type, Falco irielanops Temminck, 

 Fseicdastur Blyth, Cat. Birds Mus. Asiat. Soc. Bengal, 1849, 24. Type, Falco lacernu 

 latus Temm. 



Oh. — Similar to Uruhitmga, bat tarsus not more than twice as long 

 as the middle toe ; inner webs of only four or five outer primaries 

 cut (the cutting being a distinct emarginatiou); and nostril more nearly 

 circular, and rather vertical than horizontal. 



This genus is most similar to Uruhitinga, but presents the above well- 

 marked differences, with the addition of another and equally important 

 one, viz, the similarity of the young and adult stages in plumage. The 

 colors, too, are chiefly or largely white, instead of mainly black. There 

 is also a very close relationship to Astitriwa, but in the latter the old 

 and young stages of i)lumage are exceedingly dissimilar, the nostril is 

 very decidedly horizontal, and the emarginations of the primaries end 

 abruptly with the fourth, on which it is very distinct. The genus 

 Miqjornis, next in order of relationship, is still more remotely allied. 



The sternum of L. semiplumhetis most resembles that of Asturina 

 plagiata (it has not been compared with that of A. nitida), from which it 

 differs maiulj' in smaller size. That of Eupornis (rujicauda) differs con- 

 spicuously^ in much greater posterior breadth and larger foramina, 

 which in the other two are sometimes nearly or quite obsolete, and 

 always small. 



LECJCOPTEENIS GHIESBEECHTI. 



Buteo gJiiesh-ecliH Dubus,.Eso. Orn. 1843, pi. 1.— Gray, Gen. fol. sp. 18.— Strickl. Orn. 



Svn. i, 1855, 36.— Sc£. P. Z. S. 1857, 227 (Southern Mexico).— Scl. & Salv. Ibis,. 



1859, 217.— Lawr. Ann. N. Y. Lye. vii, 1861, 289.— Salv. P. Z. S. 1867, 158 



(Veragua).— Gray, Hand List, i, 1869, 8.— Sumichrast, Mem. Bost. Soc. N. H- 



i, 1869, 560 (Vera Cruz, hot reg.). 

 Leucopternis r/Mesbreghti Bonap. E. Z. 1850, 481 ; Consp. 19.— Scl. & Salv. Ex. Orn. 



1868, 121 ; Norn. Neot. 1873, 119.— Salv. P. Z. S. 1870, 250 ; Ibis, 1872, 242. 

 Tachytriorchis (jMesbrechti Bon. C. E. sli, 1855, 651. 

 Asturina ghiesbrechti Schl. Mus. P.-B. Astarince, 1862, 11. 

 Urnbitinga ghiesbrechti Shakpe, Cat. Ace. B. M. 1874, 217. 



Mab. — Middle America, from Panama to Mirador. 



AVing, 12.00-15.25; tail, 8.50-9.50; culmen, 1.05; tarsus, 2.80-3.65; 

 middle-toe, 1.50-1.70. Fourth or fifth quills longest ; first shorter than 

 seventh, sometimes shortest. Almost entirely pure white ; a broad 

 zone across the tail near its end, and a portion of the primaries, prim- 

 ary-coverts, and alulse deep black. Adult: — Basal half or more of the 

 primaries white; no bars on the wing. Young: — Primaries black 

 nearly to the base, or else the white portion barred with black : wing- 

 coverts more or less barred with black on the lower feathers. Loral 

 bristles and streak behind the eye black. In the youngest specimens^, 

 the black portion of the primaries barred with paler. 



