The RAVEN COCKATOOS (_Calyptorhynchus_) differ very materially from all other species not only in the colour of the feathers, but in their form. The beak is short, crescent-shaped, and sloping, owing to the great breadth of the lower jaw; the wings are large and broad, reaching only over the first third of the long, strong, and rounded tail; the crest is comparatively small. The Raven Cockatoos, or Geringeroes, are found exclusively in New Holland, and there only in certain districts. Gould, the great explorer of Australian ornithology, mentions six species in his masterly work, and gives a tolerably full account of their mode of life; there is, however, great similarity between them, and the following observations may be considered as applicable to all. The Raven Cockatoos are truly _tree_-birds, feeding principally upon the seeds of the Eucalypti, and other trees indigenous to the country, but, unlike other parrots, they will occasionally eat large caterpillars. Another peculiarity is that they only congregate in small parties consisting of not more than from four to eight individuals, and never assemble in considerable flocks. Each part of Van Dieman's Land has its peculiar species. The manner in which the Raven Cockatoos feed is also very peculiar. Some species break off the little twigs of the fruit trees while eating, apparently out of mischief; and all use their sharp beaks to draw the concealed living insects--principally larvæ--out of the wood. The large caterpillars which they obtain from the gum-trees do not always satisfy their hunger; they wage war upon the grubs that lurk deep in the wood, dextrously stripping off the bark and picking large holes in the branches until they reach their prey. Some species prefer insects to any other kind of nourishment, whilst others subsist upon seeds, principally those of the Casuarinæ and Banksias. Fruit they seem to despise, although they destroy much out of pure mischief, plucking it before it is ripe, to the great annoyance of the owners. So far as we know, the Geringeroes breed exclusively in the holes of trees, always choosing the highest and most unapproachable trunks, and invariably such as the natives cannot climb. They prepare no regular nest in the holes which they select, or at most only collect chips of wood from the ground, wherewith to line the interior. They lay from two to five tolerably large eggs, 1 2/3 inch in length and 1 1/3 inch broad. Besides the attacks made upon them by man, the Raven Cockatoos often become victims to birds and beasts of prey. Europeans do not prize their flesh very highly, but by the natives it is esteemed a delicacy. BANKS' RAVEN COCKATOO.