Another singular creature, a kind of springtail, known as _Tsikòndry_, is found on the branches of certain trees. The tail, which is about half-an-inch long—a little longer than the body of the insect—is a remarkable and curious appendage. This tail consists of a tuft of white threads, somewhat divided and fluffy at the tip, and which, at the pleasure of the insect, can be raised or lowered or spread out, the threads radiating in a circle from the root. This tail is so exactly like a lichen in appearance as thoroughly to deceive the eye. Unless a branch on which a number of these tsikòndry are seated is accidentally shaken, causing them to spring off, they would be passed by as lichens. The leap or spring is effected by a jerk of the tail. [Sidenote: PREVOST’S BROADBILL] I have already pointed out somewhere in this book that Madagascar is a kind of museum of several forms of animal life found nowhere else in the world; for among mammals there are some of the lemuridæ, especially the aye-aye; also some of the centetidæ; among the insects, the uranid butterfly; while there are several birds, which are isolated, having no near relation, so that new genera, and even new families, have had to be formed for their classification. Among these latter, and inhabiting the eastern forests, is Prevost’s broadbill (_Euryceros prevosti_). The zoological affinities of this remarkable bird were for long a puzzle to ornithologists; but it is so different from the wood-swallows, starlings and shrikes, which groups are nearest to it, that the French naturalists have formed a special family (_Eurycerotidæ_) for this solitary genus and species. This bird is remarkable for a beak formed like a very capacious helmet, strongly compressed and swelled towards the base, which advances to just as far as the eyes; and its very convex edge is terminated by a sharp hook. This extraordinary form of the beak is seen best in the skeleton, in which the beak is seen to be considerably larger than the skull. The bird is as large as a starling, velvety black in colour, with a saddle-shaped patch of light brown on the back. The large beak is steely-blue in colour, and pearly, like the inside of an oyster shell. Such specialised birds—as well as the other peculiar forms of life—speak of high antiquity and of the long isolation of their habitat from continental influences.