The circular system of Nature has been so fully demonstrated, that it must now be received as the first great truth in Natural History. As, therefore, there can be but _one_ natural system, it necessarily follows that all combinations of groups, whether large or small, which do not pretend to exhibit such a disposition, must be more or less artificial classifications. We allude to this our opinion, as explanatory of those principles which have influenced the views indicated here of M. Cuviers _Pectinibranchi_; the more so, as we shall be obliged to characterize many new divisions, and to reform others, without the immediate opportunity of explaining our reasons. In another work we hope to enter on such details; and to shew we have been guided, in this matter, by more weighty considerations than mere individual opinion. * * * * * * [Illustration: TODUS _viridis_. _Green Tody._] TODUS viridis. _Green Tody._ ---- Family Todidæ. See Pl. 41. PUBLISHED GENERA. Fluvicola. Nengetus. Alecturus. Muscicapa, (_pars_). Conopophaga. Platyrhynchus. Todus. Eurylamus. Querula? Psaris. Pachyrhynchus. GENERIC CHARACTER. See Lesson, Man. 1, p. 178. ---- SPECIFIC CHARACTER. _Bright green, beneath whiteish; throat scarlet; sides of the body rosey; under tail covers yellow._ Todus viridis. _Auct._ Mus. Paris. Nost. ---- This singular little bird has long excited the particular attention of those naturalists who study the affinities of groups, more than the details of species. It is a native of the West Indian Islands, and although stated to be not uncommon, the accounts given of its manners are perfectly contradictory. One author asserts that it is almost always seen upon the ground, from whence it receives the name of _Perroquet de Terre_: another, that it only frequents the "lonely part of moist places" (woods?), where it sits in a couched manner, with its head thrown considerably back, and is so stupid, as almost to be taken by the hand. M. Vieillot confirms part of the latter particulars, although he repeats, without denying, the former. In our opinion the last is entitled to the most credance, although it is contradictory to the idea of this being a terrestial bird.