178 



middle toe, 1.25-1.35. Inner webs of only four outer primaries dis- 

 tinctly emarginated; third to fifth quills long-est; first shortest. Tail 

 nearly even, the lateral pair of feathers slightly the shortest. Adult: — 

 Entire upper surface, including the side of the head and neck, uniform 

 dark plumbeous. Tail black, crossed at a little beyond the middle by a 

 narrow, continuous band of whte, and sometimes with a second, less 

 continuous, band, nearer the base. Entire lower parts, including the 

 chin and throat and lining of the wing, continuous pure white, the sides 

 of the breast, and sometimes the throat, with a few fine shaft-streaks of 

 dusky. Inner webs of the primaries ashy, barred with dusky beyond 

 their sinuations. Bill slate-black, the basal two-tbirds of the lower 

 mandible and that portion of the upper below the cere pale yellow ; 

 cere, rictus, and base of lower mandible bright orange-red; tarsi and 

 toes deep reddish-orange ; claws black. 



The vaiiations in the plumage of this species consist mainly in the 

 presence or absence, and amount when present, of plumbeous wash on 

 the outer side of the tibise, and the streaks of the same on the throat. In 

 No. 64913, the outer side of the tibia3 is almost wholly plumbeous, while 

 in JS^o. 66331 it is entirely absent ; in the former, each feather of the 

 throat has a distinct dusky shaft-streak, while in the latter the throat is 

 immaculate. Other specimens are variously intermediate between these 

 extremes. 



No. 66331 differs from all others examined in having two bands on 

 the tail, instead of only one ; these are both well defined, though the 

 anterior one is not, like the posterior one, continuous. No other differ- 

 ences, however, can be detected, while in other specimens this second 

 band is found indicated by transverse white spots on the inner webs. 



List of specimens in United States National Museum. 



d 

 f> 



d 



a 

 '3: 



o 



w 



n 







Locality. 



Wlien col- 

 lected. 



From whom received. 



47364 



'562' 



160 

 552 



""35' 

 265 



"265 



cT ad. 



— ad. 

 cf ad. 

 ? ad. 



— ad. 



- ad. 

 d ad. 



- ad. 

 ? ad. 



^ 



April 4. 1867 



, 1873 



, 1873 



, 1873 



, 1873 



, 1873 





64941 



do 



Prof Wm. M. Gabb. 



6494-2 



do 



Do. 



64943 



do 



Do. 



66334 



do 



Do. 



66335 



Costa Rica (Old Harbor) 



. Do. 



67860 





Do. 



67863 



do 





Do. 



67864 



do 





Do. 











Oilier specimens examind. — In. mus. G. N. Lawrence, 3 (Panama) ; R. Eidgway, 1 

 (Costa Rica) ; total, 13. 



LEUCOPTERNIS PRINOEPS. 



Leucopternis princeps Scl. & Salv. P. Z. S. 1865, 429, pi. xxiv; Ex. Orn. 1868, 122; 

 Nomencl. Neot. 1873, 119.— Lawr. Ann. Lye. N. Y. is, 1868, 133.— Salv. Ibis, 

 1872, 241-243. 

 Biiteo princeps Gray, Hand List, i, 1869, 9. 

 UruUtinga p7-inceps Sharpe, Cat. Ace. Brit. Mus. 1874, 220. 



ffaJ). — Costa Eica (mountainous districts). 



Wing, 11.00-15.20; tail, 7.50-9.00; tarsus, 3.25-3.80; middle toe, 2.90. 

 Fourth quill longest, the fifth scarcely shorter; first 3.50 shorter than the 



