INTRODUCTION. 
vu 
feathers. With respect to the brown colouring of the plumage, there are, it is true, one or two 
I 
exceptions to the rule, but none to the absence of the barring of the tail-feathers, when ac- 
companied by the former character. 
In conclusion, I may observe, that the sub-genera into which the Trogons are now sub- 
divided, are, as it appears to me, perfectly natural ; and I consequently subjoin a synoptical 
table, with the species arranged under the sub-genera which have been proposed by Mr. Swain- 
son, while at the same time in the body of my work I retain the generic name of Trogon, 
universally applied to the whole family. 
Previous to the commencement of this Monograph, the number of described species 
amounted only to twenty-two ; to these I have added and characterised twelve others new to 
science ; among which are three additional species of the sub-genus Calurus, of which only two 
were previously known, and those confounded under one name. The total number, therefore, 
of species now known is thirty-four, twenty-three of which are inhabitants of America and its 
islands, ten of the Indian Islands and India, and one of Africa. 
