The Trogons are found only in the dark primeval forests of the Tropics; shunning the haunts of man, and living in solitude and silence. It is not, therefore, to be wondered at, that their peculiar economy should be shrouded in mystery, or that the naturalists of Europe should be much perplexed in finding them a place in their artificial or their natural systems. Our researches in Tropical America, will enable us to communicate, in the forthcoming volume of Northern Zoology, some very singular information on these birds, which we shall not now anticipate. The species are much more numerous then is imagined, but they are, perhaps, less understood than those of any one group of Ornithology. Males of different species are classed as the same, while their females are considered as distinct. The number enumerated in the last edition of the Synopsis of Birds as inhabiting all South America, is six; but we possess eight species from Brazil alone; besides several others, which it is impossible to identify from books. The Mexican Trogon was first described by us, from a bird, which we felt assured was a female; and this belief was soon after confirmed, by the arrival of a fine specimen of the male, to Mr. Taylor, from Real del Monte; in whose possession it now is. We shall defer a detailed account of its plumage, until we illustrate the other sex. Total length 11 in. bill nine-tenths, wings 5¾, tail 7¾, the outermost feather 3½ in. shorter. * * * * * * [Illustration: CYMBIOLA _vespertilio_. _Bat Volute._] CYMBIOLA vespertilio. _Bat Volute._ ---- Family Volutidæ. Sub-family Volutinæ. _Nob._ GENERIC CHARACTER. Shell armed with spinous tubercles, sometimes smooth but never ribbed; spiral whorls gradually diminishing in size, but not distorted; the apix thick and obtuse; pillar with four plaits. TYPES OF FORM.--1. Marmorata. Broderpia. _Sw._ (Cymbiola. _Sow._) 2. Vespertilio. Nivosa. Rutila. Aulica. Pulchra. Pacifica. 3. Elongata (?) Gracilis. Magnifica. Tuberculata. 4. ----? 5. Lugubris. ---- SPECIFIC CHARACTER. _Shell armed with spinous tubercles, pale fulvous with remote angular waved lines of brown; spiral whorls plaited; pillar with four plaits._ Voluta vespertilio. _Lam. Sys. 7. 1. p. 336._ ----