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, 1 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 



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