INTRODUCTION, 
Vll 
feathers. With respect to the brown colouring of the plumage, there are, it is true, one or two 
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. 
