66 



Bucco macrorhynchus of the Guianas is represented in South-eastern Brazil by Bucco swainsoni, 

 and in Central America, Columbia, and Upper Amazonia by B. dysoni, all, no doubt, not very 

 remote descendants from one common stock, but presenting at the present epoch sufficient 

 differences for specific separation. 



As in most such cases, the Guianan form of this little group was the first that became 

 known to science — having been described by Buffon in 1780, from examples received in Paris 

 from the French colony of Cayenne, and figured in the ' Planches Enluminees.' Gmelin's Bucco 

 macrorhi/nchus was based on Buffon's description and figures ; and his name has happily remained 

 without alteration, except as regards its generic term, to the present day. 



In British Guiana, Schomburgk tells us, Bucco macrorhynchus is a rare bird. Schomburgk 

 only met with a few individuals on the Canaku Mountains, and could get no information con- 

 cerning the habits of the species. 



From the Guianas this Puff-bird extends into the interioi', and is met with on the banks of 

 the Rio Negro. Here, however, it would likewise appear to be of rare occurrence, as Natterer, 

 during his ascent of the Eio Negro in 1830 and the following years, only obtained two examples 

 of it, one near Barra, and a second on the Eio Brancho, and gives us no details whatever of its 

 habits. Mr. Wallace, during his expedition up the same river in 1850-51, does not seem to have 

 met with it at all. 



In Upper Amazonia this species is replaced by the nearly allied Bucco dysoni (sive Bucco 

 najoensis), which, from Mr. Wallace's observations (P. Z. S. 1857, p. 582), appears to extend 

 along the south bank of the main stream to the district just above Barra. 



I have, unfortunately, before me no specimens of Bucco macrorhynchus (which is rather a 

 rare species in collections) with the sexes ascertained ; but there can be little doubt that the male 

 and female are exactly alike externally. The example from which the figure has been prepared, 

 and which is an old skin of the well-known "Cayenne" make, purchased in Paris in 1854, may 

 be shortly described as follows : — Above, the plumage is of a dull black, rather deeper in colour 

 on the head, the feathers on the back and scapularies being very finely edged with white ; a 

 narrow front and a concealed collar at the back of the neck are white. Below, the whole throat 

 and upper breast are white, succeeded by a broad black band which crosses the upper part of 

 the beUy. The middle of the lower belly is slightly tinged with pale fulvous, whilst the flanks 

 are barred with narrow black and Avhite cross bands. The under wing-coverts are black ; but the 

 inner webs of the wing-feathers, on their lower surface, are white in the basal half, the apical 

 half being, like the under surface of the tail-feathers, of a uniform cinereous. The bill in the 

 dried skins is black ; the feet are brown, with the claws dark. 



The two examples of Bucco macrorhynchus in my collection measure as follows : — 



Ko. 



Sex. 



Mus. 



Patria. 



Long, tota, 



alae, 



caudae, 



rostri 



1. 



inc. 



P. L. S. 



Cayenne. 



8-5 



4-1 



3-0 



1-7 



2. 



inc. 



P. L. S. 



British Guiana. 



9-8 



4-2 



31 



1-8 



The figure (Plate XX.) is taken from No. 1. 



