XXIV INTRODUCTION, 
described and figured by Dr. McIntosh in the “ Linnzan 
Transactions”? for 1862, p. 79. The hairs are not only 
various in form, but sometimes they will be found con- 
stant in number. Thus, in the genus Phowus, we have 
found the number of hairs on the coxe of the three or 
four anterior pairs of legs to be constant in the respective 
species. 
EXxvuVIATION AND REPRODUCTION oF LIMBS, 
The power of Crustacea to throw off their skin and 
replace it by a new one, has long been a recognized fact 
in all the higher orders. It is, however, on the authority 
of Mr. Couch, stated by Mr. Bell, in a note to his intro- 
duction to the “ Stalk-eyed Crustacea,” p. Ixi., “ that the 
families in which the eyes are sessile in their adult 
growth . . . . do not exuviate, or voluntarily throw 
off their limbs.” 
These Crustacea, however, like their higher congeners, 
renew their integumentary tissues periodically. This is 
equally true with regard to the alimentary canal, which is 
cast in connection with the skeleton. The animal shows 
no appreciable difference in its habits at the time imme- 
diately anterior to its throwing off its exuvie. It swims 
about very actively until the hour of moulting arrives, 
when it seeks a place of comparative security, where it 
may remain uninterrupted the necessary length of time 
for the completion of the process. 
In this position it grasps with the anterior pair of 
gnathopoda some fixed and conveniently secure material 
for an anchorage. Here the labour is commenced, and, 
judging by the quietness and rapidity of the process, 
appears to be one of no great discomfort. During the 
