1870.] MESSRS. SCLATER AND SALVIN ON THE CRACID, 541 
OREOPHASIS DERBIANUS. 
Oreophasis derbianus, G. R. Gray, Gen. of B. iii. p. 485, pl. 121; 
Reichenb. Tauben, p. 155; Scl. et Salv. Ibis, 1859, p. 224; Salv. 
Ibis, 1860, pp. 43, 248. 
Penelope fronticornis, Van der Hoev. Naturg. der Wirbelth. ii. 
p- 435. 
Supra niger chalybeo-nitens: caude medie fascia lata alba: subtus 
albus, nigro anguste striatus: gula et ventre imo cum lateribus et 
tibiis nigris: rostro flavo: cornu verticali et pedibus rubris: 
long. tota 36, ale 16, caude@ 15, tarsi 3°5. 
Fem. Mari similis, sed paulo minor, et cornu verticali minore. 
Hab. Guatemala, woods of the Volcan de Fuego, alt. 10,000 feet 
(Salvin). 
Mus. Brit., Vindob., S.-G. 
Sect. IV. Geographical Distribution of the Cracide. 
The Cracide are strictly confined to the forests of the New World, 
and extend from the Rio Grande of Texas on the north to the wood- 
region of Paraguay on the south. They do not occur in the Antilles, 
with the exception of Trinidad and Tobago, and on the western side 
of the Andes do not pass southward of the Gulf of Guayaquil. 
Throughout the whole of this vast area the species are thinly distri- 
buted, not more than one member of the leading divisions (Craz, 
Penelope, and Oréalida) being usually found in the same locality. 
This fact of distribution is more strictly true than would appear 
from a cursory examination of the subjoined table. For instance, 
in Guatemala we find recorded the existence of two species of Orta- 
lida. But one of these inhabits the western forests, and one the 
eastern ; they are never found together. The same is, we believe, 
the case with the three Mexican Ortalide ; and this fact is still more 
noticeable in the case of the true Craces, where each species appears 
to be confined to its own isolated area. 
In the following table, which has been drawn up to show the dis- 
tribution of the Cracide, we have divided the whole area occupied 
by the family into nine districts. We shall say a few words about 
each of them. 
1. Mexico and Central America, from the Rio Grande of Texas 
down to the Isthmus of Panama. 
In the whole of America north of Panama we find but one species 
of Crax occurring, viz. C. globicera. Of Penelope there are two 
species, P. cristata replacing P. purpurascens of Mexico and Gua- 
temala in Costa Rica and Panama. The isolated Penelopina nigra 
is only met with in the elevated forests of Guatemala. In the same 
way Chamepetes unicolor is peculiar to Costa Rica and Veragua. 
Five species of Ortalida are found northwards of Panama; but, as 
we have already explained, only one species occurs in each particular 
district. Lastly, the Oreophasis offers one of the most extraordi- 
nary instances of limited geographical distribution hitherto known, 
being absolutely restricted to the forest surrounding a single volcano, 
Proc, Zoou. Soc.—1870, No. XXXVI. 
