TEOGON. 487 



confines of the region to the limits of the Brazilian fauna, being absent in Argentina, 

 Chili, and the extreme south. Of the twenty-four species admitted in Mr. Grant's 

 Catalogue * no less than fourteen are found within our limits. Of these seven occur 

 in Mexico, some of them nearly reaching the northern frontier, and one even passing 

 it into Arizona ; six occur in Guatemala and five in Honduras. The more southern 

 forms then begin to appear, for in Nicaragua we find seven species, and eight in Costa 

 Eica and Panama. 



The only species with wide southern range is T. atricollis, which penetrates as far 

 north as the Segovia river, dividing Honduras from Nicaragua. In the south this 

 species is subject to local variations which are discussed at length below. Other 

 species passing into the southern continent are T. chionurus and T. caligatus as far as 

 Western Ecuador, both of them with close southern allies, and T. macrurm, a species 

 restricted to Panama and Colombia. The other ten species are restricted to our fauna : 

 of these, T. bairdi and T. clnthratus belong to Costa Eica and Panama ; T. chrysomelas 

 to Eastern Nicaragua ; T. mexicanus to Southern Mexico and Guatemala ; T. ambiguus 

 and T. citreolus to Mexico; T. melanocephalus to Mexico and Costa Eica and the 

 intervening country ; T. massena to Mexico and Panama and all between ; T. elegans _ 

 to the country between Guatemala and Costa Eica, and T. puella to that lying between 

 Southern Mexico and Panama. 



The genus Trogon, of which T. viridis has been considered the type, has been much 

 subdivided by various authors ; but the characters are trivial, with the exception, 

 perhaps, of Troctes of Cabanis and Heine, represented by Trogon massena. This is a 

 stouter form without white ends to the lateral rectrices, but these characters are hardly 

 of sufficient importance to render any division of Trogon desirable. 



As in JEwptilotis the upper tail-coverts are comparatively short and do not extend 

 nearly to the end of the rectrices, nor are the wing-coverts lengthened as in Pharo- 

 macrus. The central pair of rectrices are differently coloured in the sexes, those of 

 the male being of some shade of glittering green, those of the female brown or slate- 

 colour. 



The colouring of the lateral rectrices and of the females furnishes natural characters 

 for the subdivision of the genus. 



A. Rectrices utringue tres laterales plus minusve alio terminatce. 

 a. Femina supra hrunnea aut rufo-brunnea. 

 1. Trogon mexicanus. 



Trogon mexicanus, Swains. Phil. Mag. new ser. i. p. 440 (1827) ' ; Zool. 111. ser. 2, tt. 82, 107^; 

 Wagl. Isis, 1831, p. 523"; Gould, Mon. Trog. tt. 1, 2'j ed. 2. t. 7'; Scl. P. Z. S. 1859, 



* Of these we unite T. aurantiiventris with T. puella and add Mr. Eichmond's T. chrysomelas, a species 

 unknown to us. 



