DUCKBILL, or PLAT'veus. An aquatic, egg laying mammal of the order :\lonotremata. of which only one species I rnitherhynch para dOrtiR) is known. It inhabits the rivers of Aus tralia. Papua, and Tasmania. The first descrip tions of this singular quadruped were received with incredulity, and even when a stuffed speci men was brought to England. it was suspected to have been ingeniously fabricated. The whole length, including bill and tail. is usually from iS to 20 inches. The body is rather long and de pressed. the skin loose and thickly covered with glossy hair. among the roots of which there is a layer of soft short waterproof fur like that of a beaVC1'. The head is SIlla II and round, with small bright eyes, and no external ears, although the internal ears are perfectly developed. and the hearing acute: and instead of the muzzle. mouth. and teeth of an ordinary quadruped. the creature is furnished with a hill like that of a duck, hut broader ill proportion. This Meioses the long upper and lower jaws within an extremely sensi tive naked skin, grayish in color. which is mostly attached to the underlying bones, but possesses a flexible, lip-like border all round the mouth, and is raised into a frill-like fold round the base of the bill, which, in burrowing and searching for food in the mud, is turned hack so as to protect the eyes. The nostrils are situated at the extremity of the upper mandible. so that the animal need only thrust the tip of its nose out of water in order to breathe. Thelower mandible has transverse lamella.. somewhat like the hill of a dock. and each jaw is furnished with two pairs of horny plates reornules'). the forward ones like sharp ridges, while those hehind are broad and flat tened. These serve the purpose of teeth for the adults: but true cheek-teeth are present in young animals (see Proceedings of the Royal of London, vols. xliii., 1SSS: and xliv., ISS9), which "a re funct iGnal for a considerable part of the life of the animal. cutting the gum in the usual manner. and, after being worn down It• friction 1%itli food :old :and. are shed from the mouth in the Manner as are the milk-teeth of other The ridges grow up around them and take their plaec. The-, are regarded evidence that the duel: bill descended from provided wills per si.tent. 11•1•01 the ordinary kind. The tongue sahib, !tome\ t en-ile, partly covered with burnt and .t projection to%vard ithinder part which -one: to direct the food col 'vete,' into two large whom it can -.toted anti cony, niently carried to the bar 1e0 or -'inc other comfortable eating-place.
The duckbill k aquatic and a burrower, and its shows adaptation to these habits in the great strength of the bone, of the limb. and of flu pectoral girdle. The are -.hurt. the fore feet hart eaell live with -trong burrowing and a connecting membrane fur Nylijeli extend,: even beyond the but is capable of being folded back. not to impede limit use in burrow ing. The hind feet arc smaller than the fore feel : they have each lino toe- aimed with claw. and webbed. the welt not ex tend b. you.] the bast 14 the The tail i, strong, broad, and flattened, about half long it- the body. covered with longer and voa•:or and nearly naked in under surface. .1.n interesting feature the horny spurs on the heels iif the lnale. which are nioVallle and traversed 1..%- a mitotic canal opening at the point, and connected at tile i\ jilt the duet from a large gland at the back part of the thigh. The
popular belief that lin,. spurs Were ill this fanglike structure gave support. has been by the record of a case by :spicer (•On the of on the human subject inflicted by the spur, 1'I the platypus." in diays of flu Uouul I y of Tirstng ]loba•t Town. 18711). it a man who suffered prcei-ely a: if loyally poisoned. following a %%mind from the spurs of a captive duckbill. Ilow•%cr, a: the nmhe alone thee ap pendage-. they are probably used mainly in the of the nuptial 11.1nrrs. The duckbill is as thoroughly r. -pending whole life in or near rivers. but not fretpumting stagnant nor Itracki-lt It chiefly by flipper like movement- of the iv, lilted fore feet. and 41 I 11.S X% va.-y and grace. It is somewhat gregarious. but st, shy rarely to lie seen l'% ell Where %valehed for at evening. whets they "look like so 111:Illy black final tilt lb(' surface. and down directly if alarmed." Each pair dig- and ocenpie• it burrow in the bank. having usually one opening beneath the %%At r and another above it, which may rim irregularly away and upward from the -4 reant for tin or Bp1ccn yard. before the .11\ to l•lahl It into a 111011111.1T bedded with dry grass, where they -deep. rolled lilt in a ball, 11111..t ti the day. :ii d where the young :the produced. The evil nn•Il .4 burrows is notorion, in .\ I ralia. 'Fla se rarely ;2. ashore. and %viten thev .1" Waddle 11,11111t \\ WI a slipshod ;_Wit: utt those in captilill, whene ti cy exhibit dot Oily and the furniture of a neon with stirprking agility. "The food ....II" it .11111.1t le ..111:1111 anal worm, whirl} ;1 IV eaught under stator. the sand m1.1 11 -ti lle- :1t Ilse 'm11.111 being turned goer with Ile bill. The appear at first It' lie' po.it what they have collected in their elieek• pouelte,, and when these are filled they to the surfac• and quietly triturate their nical with the horny plates before swallow ing food di-covered in the mud not only by an extreme 1,1 lunch of the margin of the bill. Mit by smell thf which those studied in eapti% ity a remarkably high deVelopnient. eye, are -mall half hidden. hut perfect and useful. The I the I of a yontig puppy. hut the :1 disii0.it 11111 is getalu.
I 1 l'.‘1:01:S (T1)N. The duckbill. like other immotrente:, aetnally lass from which are hatched—a fact long disputed. and doubt fully believed by the aborigines, who wvro well acquainted with the haunt, and habits of the which they sought both a, food and for it, skin. The eggs are white, three-fourths It an inch long Ity one-half an Melt broad. the -hell is ....ft and flexible. and they contain a lire a11111111 in hint.' egg.. a few are laid at ? time. only one, and it hatched very soon it laid, mother no but milk-gland: (pett ing int() little pit. ,o tilllt the young soc111 t. he suckled by the ejection of the milk into their mouths. which in this early stage are smooth and tlesity. The young are blind and naked at birth.
v. t he treat !tient bole,' above. consult various article- by them in the Truttsuctions of the Philosophical and Zoidogical of London 1.3.2-3 ; Hower and 1.ydel:.ker. llte el stmt.:, 1.iritiq mid Loudon. I(91 1 ; wale' ions of Ire I So•it of Little„ I I Benne". of " in .t (London. 1Stti1. See .1oNcrrtfrNfr; and compare Ectiffix.%.