ANALOGY OF THE COYPU. 
479 
other peculiarities, we shall no longer be at fault in 
classification.” 
This strange position of the teats is not quite 
singular, though it has never before been remarked 
in the Capromys, Mr. Waterhouse in his beautiful 
work on the Mammalia, now in progress, thus alludes 
to the subject: — ‘‘ The female Coypu (a large South 
American Rodent of the same family) 
swims with her young on her back until they are sufii- 
ciently large to follow the parent. This habit helps 
to explain the singular position of the nipples in 
the female Coypu. Of these four were found by 
M. Lereboullet on each side of the body, and 
situated rather above the mesial line of the flanks, 
the foremost being placed behind the shoulder, and 
the hindermost in front of the thigh.” Mr. Water- 
house considers that this position of the nipples, 
rather on the sides than the under part of the body, 
will be found a common circumstance in the Hystri- 
cine division of Rodents, since he has found them so 
situated in the genera Lagostomus, Octodon, Ha~ 
hrocoma, and Nelomys. — {Nat, Hist, Mammalia, 
ii. 299.) 
The following notes by Mr. Johnston will be read 
with interest. After a minute detail of some par- 
ticulars of structure distinguishing the animal from 
the Cavies, he thus continues : — 
‘‘ The animal treads on the whole of the lower 
joint of the hind leg, from the hough, as does the 
rabbit ; it is in fact plantigrade, but its usual motion 
is very unlike that of either rabbit or rat : the former 
always, and the latter generally, moving the pairs of 
