INTRODUCTION. the Couroucous express the syllable pzo, repeated many times in succession with a powerful, yet plaintive tone. ‘Their accent almost reminds one of the wailings of a child who has lost its way, and it is thus that they cry to each other amidst the silence of the forests. As soon as the young are able to provide for themselves, they separate from their parents to enjoy that solitude and isolation which appear to constitute the supreme happiness of the species. Their aliments are composed of larva, small worms, caterpillars, coleoptera, and berries, which they swallow entire. «The male, at various ages, the female, and the young, differ in their plumage, which has given rise to the institution of more species than are really in existence.” This account of their habits I am not only in a great measure enabled to confirm from the information I have obtained respecting them while engaged upon the present Monograph, but also to add a few facts, which although trifling, and in some degree contradictory to the preceding account, will not be uninteresting. My friend Mr. John Natterer, who has had many opportunities of observing these birds in a state of nature, informs me that he has seen them, though very rarely, congregating together, and more than one species in company; a circumstance which he considers may be accounted for on the principle that instinct leads them by some migratory movement to abandon one district at a certain season of the year in search of another, where food is more abundant. These migrations, however, cannot be extensive, inasmuch as their wings are not adapted for a lengthened flight; besides which, every new district of any great extent presents us with its peculiar species ; for example, none of the species inhabiting Mexico have been found in the Brazils, and vece versa. The members of this family appear on general survey to be divided between America, including its islands, and the islands of the Indian Archipelago; two or three species only having yet been discovered on the continent of India, and those principally inhabiting the countries bordering the Indian Seas. The great nurseries for these birds in the Old World are the islands of Ceylon, Sumatra, Java, Borneo, &c., while over the whole continent of Africa