BY J. T. WILSOX. 685 



development of the hair folHcles is still in the earlier stages, and 

 that nowhere have hair-shafts as yet approached the surface of 

 the epidermis, which was perfectly naked. 



Besides Owen's two specimens the only other one known to me 

 is one which came into the possession of the late Professor W. K. 

 Parker and whose external characters were partly described and 

 a figure of it given (p. 25) in his " Mammalian Descent " (Lond. 

 1885). More elaborate drawings (life-size) of this specimen have 

 quite lately been published by Professor E. B. Poulton in the 

 Quart. Journ. Microsc. Sci., Vol. xxxvi., in connection with his 

 paper on the hairs, &c., of Oniithorhynchus. Mr. Poulton also 

 gives a list of memoirs dealing with the anatomy of portions of 

 this specimen. 



From the drawings of Parker's specimen I have estimated the 

 length of the dorsal contour line from the tip of the snout to the 

 tip of the tail as about 250 mm. It was thus very considerably 

 larger than mine, in which the same line is only 80 mm. 



One of Owen's two specimens was also much larger, so that his 

 smaller specimen is the only one with which one can rightly 

 compare the subject of the present paper. 



The specimen (which had been labelled as from the Patterson 

 River) has been very satisfactorily preserved in alcohol, as micro- 

 scopical sections subsequently made bear witness. Cellular struc- 

 ture and arrangement are well shown and karyokinetic figures 

 are abundant, at least in the epidermis. It is perfectly intact 

 with the exception of a small apparently accidental skin-incision 

 on the ventral aspect of the neck (shown in figure 3), and two 

 other very small abrasions on the skin of the back and abdomen. 

 The general integument is quite naked and marked throughout 

 by delicate transverse wrinkles, which are probably of post-mortem 

 production, and are neither so numerous nor so pronounced as 

 those figui-ed in Owen's specimen (Trans. Zool. Soc. Vol. i. PI. 

 XXXII.). The long axis of the animal is markedly curved, the 

 convexity being dorsal. The contour of the dorsal surface forms 

 rather more than a semicircle of slightly unequal curvature 

 throughout. (In Parker's specimen the contour formed nearly a 



