CHIROCEPHALUS. 
51 
first three pairs of feet, which are not yet moveable, and 
four pairs of small knobs or projections, the rudiments of 
as many other feet. After moulting for the third time, 
the first two pairs of feet have become moveable and 
foliaceous, and we can distinguish seven pairs of rudi- 
mentary feet. The eyes have become somewhat pedun- 
culated, and the body more elongated. It continues to 
moult frequently, and at short intervals, and we can trace 
the conformation gradually approaching more and more 
to that of the adult. The branchial feet become, after 
each time, more developed, the eyes more perfect, while 
the large natatory feet, which are so large and conspicuous 
when first born, are gradually converted into the pre- 
hensile antennae in the male, and the cephalic horns of 
the female. 
In January 1849, I had several specimens of female 
Chirocephalus, which had been taken at Blackheath on 
the 25th of December previous. These deposited their 
eggs in the vessel in which they were kept, and though 
the mothers died in about a fortnight after they were 
taken, the ova were matured in the vessel, and the young 
hatched. Upon submitting a mature ovum to inspection 
under the microscope, I found the young animal inclosed 
within a pure, transparent envelope, which again had evi- 
dently had an external thicker and opaque coat over it. 
This was more than half detached (t. V, f. 2). A few 
hours afterwards, I found that this thick external covering 
was completely separated, and the young was then merely 
inclosed in the transparent case. Twelve hours afterwards 
it was still within its envelope, but it completely filled 
it lengthwise. It was balloon-shaped (t. V, f. 3), per- 
fectly transparent, and colourless, and the young animal 
pushed frequently its head against the top of its case, as 
if trying to burst it open. It could turn itself round, 
however, from one side to another. In twenty-four hours 
more I found the young animal just launched from its 
prison into the world. Two or three hours after its birth 
I submitted it to inspection through the microscope. At 
