1865.] MR. P. L. SCLATER ON A NEW ACCIPITRINE BIRD. 429 
pallide fulvescentibus ; cauda unicolore nigra; uropygio isa- 
bellino, gastreo toto intense fulvo; subalaribus nigris ; sub- 
caudalibus fulvis ; rostro et pedibus nigris. 
Long. circa 6", rostr. 6!", al. 3! 7", caud. 2" 3!", tars. 14!"', 
Jun. Fusco-brunnea; subtus pallidior, uropygio fulvescente. 
Hab. Windvogelberg, in Africa merid. inter. (Capt. Bulger). 
3. DescrirTion or A New AccipitrINne Birp rrom Costa Rica. 
By P. L. Scuater, M.A., Pu.D., F.R.S., SecRETARY TO THE 
Society. 
(Plate XXIV.) 
My friend Mr. Osbert Salvin has requested me to bring before the 
notice of the Society this evening a specimen of a very fine and well- 
marked species of Accipitrine bird, which he has lately received 
from Costa Rica, This bird was procured by Enrique Arcé—the 
same collector who obtained the several conspicuous novelties which 
Mr. Salvin described in these ‘ Proceedings’ for last year*, at ‘Tu- 
currique. Mr. Salvin proposes to call it 
LEUCOPTERNIS PRINCEPS, sp. nov. (Pl. XXIV.) 
Plumbescenti-nigra, plumis ad basin albis: cauda albo uni- 
Sasciata : abdomine toto et alarum tectricibus inferioribus albis, 
nigro frequenter transvittatis : rostro pallide corneo, cera flava: 
pedibus aurantiacis, unguibus nigris. 
Long. tota 20 poll. Angl., alee 14°3, caude 8-0, tarsi 3°5, dig. int. 
cum ungue 2°5, dig. med. c. ung. 2°9, dig. ext. c. ung. 2°6, dig. 
post. c. ungue 2°4; rostri a rictu ad ap. mand. inf. linea directa 1-5. 
Hab. Costa Rica, in montibus. 
This bird is very distinct in coloration from any other species of 
the group with which I am acquainted. The bill is strongly hooked 
at the tip, and the margins of the upper mandibles festooned. The 
nostrils are large and open, regularly oval; the cere is yellowish in 
the dried skin, thinly planted with black bristles, which also occur 
on the sides of the lower mandible. The whole plumage above and 
below to the middle of the breast is nearly uniform plumbeous black, 
rather lighter on the edgings of the feathers. At their bases the 
feathers are white, which colour shows through, especially on the 
head and nape, when the feathers are slightly disturbed. The tail is 
crossed by a narrow white band in the middle of its exposed portion. 
Other less complete bands follow towards the base of the tail; but 
the whole apical portion of the tail is uniform black, like the back. 
Externally the wings are uniform, like the back ; but the inner (and 
partly the outer) margins of the secondaries are broadly barred with 
white. The whole belly, from the middle of the breast to the lowest 
tail-coverts, is white, thickly barred across with narrow black bands, 
there being seven or eight of these bands on each feather. The 
* See P. Z. S. 1864, p. 579. 
