CHIROCEPHALUS. 
53 
On the 10th, at six p. m., ninety-six hours after birth, 
it had become somewhat increased in length. The knobs 
were nine in number, the four uppermost being free from 
the body, and setiferous at the extremity, and much in- 
creased in length. The antennae had diminished in length 
in proportion to the body. 
On the 11th, seven p. m., about 120 hours after birth, 
I found it had undergone scarcely any change in ap- 
pearance. 
On the 12th, 144 hours after birth, I found it en- 
veloped in a covering of filmy, slimy stuff, which had 
been floating about in the water. It had, notwithstand- 
ing, gone on increasing in development. The knobs were 
eleven in number ; the first six pairs free, and the three 
or four superior pairs distinctly lamellar. The lateral 
eyes had become distinctly pedicled, and on each side of 
the median eye there was a slight projection or knob. 
I was unfortunately prevented carrying my observations 
further. 
The female begins to lay before she has attained her 
full size, and lays several times during the season. Each 
time the ova are transmitted from the internal to the ex- 
ternal ovary, the animal throws off its skin. 
1. Chirocephalus diaphanus. Tab. Ill, figs. 1, 2. 
Chirocephalus diaphanus, Prevost, Journ. de Phys., 1803, lvii, 37, 
1. 1, f. 1-3. 
— Jurine , Hist. Monoc., 201, t. 20-22. 
Branchipus Prevostii, Fischer, Bull. Soc. Imp. Nat. Moscou, 
vii, 1834. 
Chirocephalus Prevostii, Thompson, Zool. Research., fasc. vii, t. 3, 
f. 4, 5 ; t. 4, f. 1, 1834. 
Branchipus chirocephalus, Guerin, Icon. Reg. An. Crust., t. 33, f. 3. 
Branchipus diaphanus, M. Fckoards, Hist. Crust., iii, 368. 
Branchipus paludosus, Desmarest , Consid. gen. Crust., 389, t. 56, f. 2. 
— Lamarck, Hist. An. s. Vert., 2d. edit., 
v, 198. 
