ORNITHORHYNCHUS 709 the Zoological Society " of London (descrip- tions of Mr. Sclater and others), and the vari- ous illustrated works, the results of the nation- al expeditions sent out by England, France, the United States, Russia, Holland, &c. Among the magnificent works may be mentioned the 1,008 planches enluminees of Buffon (fol., Paris, 1770-'86); the 600 planches coloriees of Temminck ; Le Vaillant's birds of Africa, par- rots, birds of paradise and rollers, promerops, and rare birds of America and India, in all about 570 plates ; Edwards's 362 plates of un- common birds ; Vieillot and Audebert's near- ly 180 plates of birds of brilliant plumage; Gould's series of the birds of Australia and Europe, the humming birds, trogons, &c. ; and Audubon's 435 plates in folio of North American birds. America has not produced any original system of classification of birds ; but the writings of Nuttall, Wilson, Bonaparte, Audubon, De Kay, Baird, Ooues, Allen, Brew- er, Lawrence, and Cassin have well illustrated the ornithology of this country ; many new and beautiful species have been added since 1840 ; and Messrs. Baird, Brewer, and Ridgway are now (1875) publishing a new work on North American birds. There are probably 6,000 species of birds, of which about five sixths are known. Birds existed on the earth before the present geological epoch, but their remains in a fossil condition are comparatively rare. The oldest date claimed for birds is the new red sandstone epoch, where in the Connecticut valley Dr. Hitchcock and others have found tracks which they pronounce those of birds; but many suppose them to have been made by reptiles, and for various reasons it is doubtful if any birds existed at that epoch. Birds with reptilian characters certainly did appear in the upper oolite (see ARCELEOPTERYX) ; birds of prey have been found in the tertiary and dilu- vial; passeres in the same; gallince, rare in the tertiary, are abundant in the diluvium ; among cursores, the genus rhea has been found in the caverns of Brazil, and the dinornis, epy- ornis, &c., have been met with in alluvial de- posits ; the palmipedes are still earlier, and the genus cimoliornis (Owen), coming near the al- batross, has been found in the chalk of Europe. ORNITHORHYNCHCS (Gr. dpvis, a bird, and t>vyxSi a beak), a genus of implacental mam- mals of the order monotremata, which seem to form a connecting link between mammals and birds, and in some respects having affinities even with reptiles. A single species only is described, the platypus anatinus (Shaw), or ornithorhynchus paradoxus (Blumenb.), the duck-billed platypus of English writers, the water mole of the colonists, and the mallan- gong of the natives ; it inhabits the fresh-water streams of Australia and Papua. It is from 18 to 22 in. from the end of the jaws to the point of the tail, the latter being about 5 in. ; the color above varies from ruddy to dark brown, and is whitish below ; the jaws are enclosed in a horny sheath, very sensitive, like the bill of a duck, and have two horny teeth on each side above and below, flat, rootless, composed of perpendicular horny tubes; the snout is flat and broad, the lower jaw the narrower and shorter and provided with lamellae on the sides; the eyes small and brilliant; ears not Ornithorhynchus paradoxus. apparent externally, with an aperture which can be opened or shut at will ; the tongue con- sists of two parts, the posterior broad, flat, with soft papillae and a free process bearing two pointed horny teeth, the anterior narrow and covered with upright points longest and sharpest toward the tip ; the nostrils are at the end of the upper mandible ; cheek pouches are present, and a bulb on the back of the tongue prevents the contents of the mouth from pass- ing into the larynx ; the fur is soft and thick, like that of the otter. The legs are short, and the feet five-toed, webbed, and furnished with strong claws ; the fore feet are the strongest, and their loose webs extend beyond the claws ; the hind legs are armed with a sharp, conical, bony spur, with a corneous investment, per- forated for the passage of a duct communica- ting with a gland situated on the thigh ; the tail is flat, broad, and beset with rigid hairs. As the name of the order imports, the alimen- tary, urinary, and reproductive organs open into a common cloaca, as in birds; mamma- ry glands are present, secreting milk for the nourishment of the young, which are born blind and naked ; there are no prominent nip- ples, and the mammary openings are contained in slits in the integument; the beak in the young is short and flexible, adapted for suck- ing; M. Verreaux (Revue zoologique, 1848) says the young, when they are able to swim, suck in the milk from the surface of the water into which it is emitted. The shoulder bones are unlike those of other mammals, and are in- termediate in arrangement between those of birds and reptiles ; in many points of the gen- erative system, also, there are ornithic and rep-
