1864.] DR. P. L. SCLATER ON A NEW CHAUNA. 75 
The following diagnoses will, I think, serve to distinguish the 
three species of Chauna :— 
1. CHAUNA CHAVARIA. 
Parra chavaria, Linn. 8. N. i. p. 260. 
Palamedea chavaria, Temm. PI. Col. 219; Burm. Syst. Ueb. iii. 
p- 397. 
Cinerea: collo undique obscuriore : ventre albo, cinereo flammu- 
lato. 
Hab. In Brasil. merid. et Paraguay. 
This appears to be the largest and most lightly coloured of the 
three forms of Chauna. The black ring is ill-defined, and placed 
much lower down the neck. In the two succeeding species the neck 
is wholly black up to the white throat and cheeks. The belly of 
this species is whitish, with indistinct flammulations of cinereous. 
2. CHAUNA NIGRICOLLIS, sp. nov. (Pl. XI.) 
Chauna chavaria, Sclater, P. Z. 8. 1863, p. 377. 
Saturate nigricanti-cinerea: gula et genis circumscripte et di- 
stincte albis : collo undique et late nigro: ventre cinereo, crisso 
albo. 
Hab. In Noy. Granada, ad ripas fl. Dekke. 
In its distinct white throat and black neck, this form agrees more 
nearly with Chauna derbiana, but in general coloration rather ap- 
proaches the Brazilian C. chavaria. It appears to be decidedly 
smaller in dimensions than the latter species, and I see no traces of 
the partial denudation of the throat which appears to obtain in 
adult examples of Chauna chavaria. 
As no Chauna, as far as I am aware, occurs in Guiana or in any 
part of the Amazon valley, it would seem that the areas of these two 
species are separated by a considerable interval. 
3. CHAUNA DERBIANA, G. R. Gray. 
Chauna derbiana, Gray & Mitch., Gen. Birds, pl. 161. 
Nigra: gula genisque circumscripte albis: rostro et pedibus ru- 
bris. 
Hab. In Guatemala, prov. Peten. 
The only two specimens of this scarce bird in England are, I be- 
lieve, those in the Derby Museum at Liverpool, from one of which 
the figure was taken. Mr. T. Moore, the Curator, has kindly fur- 
nished me with the following note respecting the precise locality of 
this species, which is of interest, as no details whatever have yet 
been published on the subject :— 
“The original specimen of Chauna derbiana, that from which the 
figure in Gray’s ‘ Genera’ was taken, was obtained by Mr. J. Bates, 
who was sent out by the late Lord Derby with the primary object of 
procuring and importing alive the Meleagris ocellata. 
“The specimen is labelled ‘J. Bates, Sept. 1843, Peten,’ by his 
