“ Setting 1 aside the name of T. rufus as inappropriate, and T. lepturus, proposed by Swainson, which is a 
pure synonym of T. atricollis, as well as the MS. title of Lichtenstein’s quoted by Dr. Cabanis, the other 
names given to this bird all refer to races or supposed races occurring in different districts of its range. 
Thus the South-Brazilian bird has been separated by Herr von Pelzeln as T. chrysochlorus, and the Central- 
American as T. tenellus by Dr. Cabanis, Vieillot’s name, T. atricollis being applicable to the race found in 
Guiana and the valley of the Amazons. 
“ Having on several occasions, both by myself and with Mr. Sclater, closely examined numerous 
specimens of this bird from all parts of its range with a view to test the right of these various races to 
rank as species, I have always come to the conclusion that such a rank could not be granted them without 
rendering it exceedingly difficult, if not impossible, to assign to every specimen its right name. To show 
how varied is the state of opinion on this point, I may add that Dr. Cabanis, Mr. Gould, and Mr. Lawrence, 
uphold the distinctness of T. tenellus , the two former rejecting T. chrysochlorus as distinct from T. atricollis. 
Dr. Finsch agrees with Herr von Pelzeln in maintaining the specific rank of T. chrysochlorus, suggesting 
(as it appears to me rightly) that the birds described in the ‘ Museum Heineanum ’ really were 
T. chrysochlorus and not T. atricollis. I think myself that the differences observable are so slight that 
they may be regarded rather as tendencies to vary in a particular direction in a particular locality than 
as fixed, definite, specific characters. At the same time I must say that, if their separation be maintained, 
the South-Brazilian has equal, if not stronger, claims to be considered distinct from the Guiana race than 
the Central-American has. The Guiana bird is in fact almost precisely intermediate between the races found 
in Brazil and Central America. The white hands of the tail are widest and fewest in T. tenellus, narrowest 
and most numerous in T. chrysochlorus. The central tail-feathers have a bluish shade in T. tenellus, and are 
most bronzy in T. chrysochlorus. The wing-coverts are coarsely mottled in the former, finely in the latter. 
In all these points T. atricollis is intermediate.” 
Leaving the northern form, T. tenellus, to be noticed in a separate article. I will now trace the range of 
T. atricollis, including with it T. chrysochlorus. 
Buffon alludes to its occurrence in Cayenne. It also occurs in Demerara, where Schomburgk met with 
it; but westwards of this district I have not yet come across any recent allusion to its occurrence in 
Venezuela or Trinidad, though Levaillant mentions its presence in the latter island. Throughout the valley 
of the Amazons it is found apparently in abundance. Natterer obtained nine examples during his voyage at 
Nas Lages, Borba, Marabitanas, Cocuy, and Barra do Rio Negro; while on the Upper Amazons, or 
Solimoens, Spix met with it, and subsequently Mr. E. Bartlett within the frontiers of Peru at Chamicurros* 
In Southern Brazil Prince Maximilian found it at Bahia, whence, and also from Rio de Janeiro, numerous 
specimens are constantly sent to Europe. In the province of Sao Paulo Mr. J. F. Hamilton found it pretty 
generally distributed throughout the forest, but not abundant in any one locality. He adds that it is of 
rather solitary habits, and that he never saw two together. In the same district, at Ypanema, Natterer 
secured fifteen examples, and upon these he bestowed the name chrysochlorus, afterwards described by Herr 
von Pelzeln. Trogon atricollis is also found still further south, in the province of Rio Grande do Sul, whence 
Mr. Rodgers has sent us specimens. 
The figures in the Plate are of the natural size. 
