OBSERVATIONS UPON THE ANATOMY OF THE MUZZLE OF 
ORNTTHOREYVNGHOS* 
By J. T. Witson, M.B., Proressor or Anatomy, Untversiry or Sypney, anp C. J. 
Martin, M.B., B.Sc., Demonstrator or Puystotoay, University or SyYpDNEY. 
(Plates xxu.-xxu.) 
The term “duck-bill” as commonly applied to the muzzle of the Platypus seems to 
have been the source of a certain degree of misconception in regard to the characters 
of that portion of the animal, not merely on the part of the unlearned multitude 
but of not a few eminent comparative anatomists. 
This so-called “ duck-bill” is deseribed by Huxley (1) as “a flattened muzzle 
resembling the beak of a duck.” This quite correctly expresses the form and general 
appearance of the muzzle, but the integument is by no means “leathery” as this 
author terms it. Owen (2), too, speaks of the lips as “ transitorily manifested, it is 
true, at the suckling period, but which soon degenerate into the pergameneous border 
of the beak,” and again (p. 384) “the jawbones are invested by a smooth coriaceous 
integument.” Such terms as “leathery,” “pergameneous” and “coriaceous” are 
inappropriate and misleading, but they are certainly less so than the term “horny” 
which is used by some other authors. 
Thus, Flower (3) speaks of the premaxille as supporting the “ partly horny 
partly membranous beak which fills up the space between them and extends consider- 
ably on each side and in front.” Mivart, too (4), in his chapter on the “external 
skeleton,” writes thus :—‘“ The epidermis of the outside of the muzzle and jaws may 
also be converted into horn as in the beak of birds and in that of the turtle. Asa 
remarkable exception, the same thing may take place in man’s own class: this we see 
by the duck-billed Platypus, which really has a horny beak very like that of a duck.” 
As a matter of fact, the epidermis of the muzzle of Platypus is no more “ horny” 
than that of a dog’s nose, from the texture of which indeed it does not greatly differ. 
The sole explanation intelligible to us of such applications of the epithet “horny” 
to the skin of the muzzle of Platypus is that the statements have been based upon an 
examination of preserved specimens which had undergone partial desiceation—which 
* An abstract of this paper was published in the Abstract of Proceedings of the Linnean Society of N.S.W., 
August 31st, 1892. 
