OF THE ORNITHORHYNCHUS PARADOXUS. 
537 
Geoffroy (Mem. du Museum, PI. I. fig. 6.) the right uterine 
tube is omitted, and the left is made to terminate in a point 
without any indication of the Fallopian orifice or of the ovarian 
capsule. 
Fig. 2. A portion of the integument from the abdomen of the Spiny Ant- 
eater ( Echidna hystrix, Cuv.) showing at a, the mammary areola. 
Fig. 3. a. The mammary gland of the Echidna hystrix. 
b. The panniculus carnosus. 
c. The integument. 
This specimen was taken from a young female nearly arrived at 
maturity, but which had probably never been impregnated ; it 
consequently exhibits the gland in a low stage of development. 
The glands are two in number as in the Ornithorhynchus, and 
are situated about half an inch from the mesial line of the ab- 
domen, and three inches and a half anterior to the cloaca. They 
are each composed, as in the Ornithorhynchus, of numerous 
elongated lobes, which converge towards the mesial line, their 
ducts penetrating the integument, and forming by the aggre- 
gation of their orifices a small areola externally. This areola 
is more easily distinguished in the Echidna, from the hairs on 
the abdomen being more scattered ; it is not situated on an 
eminence, nor surrounded by any erectile tissue : it is made up 
of about sixty orifices. The lobes of the gland are proportion- 
ally broader and shorter than in the Ornithorhynchus. A strong 
panniculus carnosus is similarly interposed between them and 
the integument, and the fibres of this muscle separate to allow 
the ducts to pass through, as represented in the Plate. The 
lobes are not mere ccecums, but present under the lens a similar 
texture to those in the Ornithorhynchus. 
Plate XVIII. 
Fig. 1. A portion of integument from the abdomen of the Ornithorhynchus 
paradoxus, with the hairs removed so as to exhibit the mammary 
areola. 
