5<i8 Singular StruSIure of the Head of the Omithorhpchut fttradoxut, 



equally broad with the upper : this has a ferrated edge ; but the ferrse are confined to the 

 foft part, not extending to the membrane covering the bone, and are not met with in the 

 upper one. The extent of -the lips beyond the bones, is diftinftly marked in the 

 drawings. 



There is a very curious tranverfc fold of the external black fmooth flcin, by which the 

 beak is covered, projefting all round, exadlly at that part where the beak has its origin. 

 Its apparent ufc feems to be to prevent the beak being puflied further into the foft mud, 

 in which its prey may He concealed, thanup-to this part, which is fo broad that it muft 

 completely ftop its progrefs. 



The nerves that fupply the beak, in their general courie, f^ze, and number, feem.very 

 •lofcly to correfpond with thofe of the bill of the duek. 



The cavity of the fkuU bears a greater general refemblance to that of the duck than 

 of quadrupeds : there is a very uncommon peculiarity in it, which is, that th&re is a 

 bony falx of fomc breadth, but no bony tentorium. This is met with in no quadruped 

 that I know of: it is found in a fmall degree in fome birds, as the fpoon-bill, and the 

 parrot j but not at all fo as to refemble the falx in this animal. 



The orifice of the eye lids is uncommonly fmallj for the Cze of the animal j but the eye 

 itfelf was not in a flate to be examined. 



The external opening of the ear was fo final! as not readily to be perceived: it 13 

 fimply an orifice ; but the meatus enlarges confiderably beyond the fide of the opening, and 

 pafies fome way under the flcin before it reaches the organ, which in this fpecimen had 

 been deftroyed. In the duck, the orifice leading to tlie ear is very large, when compared 

 with the opening in this animal. 



When we confider tlie peculiarities in ^ ftru£lure of the nofe of this animal, which- 

 lives in water, it is natural to conclude the organ is fitted to fmell in water, and the ex- 

 ternal noftrils are fo placed, to enable it to difcover its prey by the fmell j for that purpofe,, 

 the animal can apply its nofe, with great eafe,. to the fraall receiles in which its prey m.ay 

 be concealed. 



The ftru6lure of the beak is not fuch as enables it totake a firm hold ; but, when the 

 marginal lips are brought together, the animal will have a confiderablc. power- of fudlion,. 

 and in that way may draw its prey into its mouth* 



EXPLANATION ,QF Tiie. EIGURES. 

 Plate XXII; . 



Fig. I, A, view of the beakj. to fliow the fituatioa of the openings of the external! 



apflrils, marked rt a. 



Fig. 2. Another view of the beak,, expofing the under portion- 

 Fig. 3. A lateral view, to fhow the opening of the lips, and the fituation of the eye and! 



tar. a. The eye k. The ear-. 



