a a 
108 
The nerve supplying the antennules has a similar branch- 
ing at its termination to that of Lepeophtheirus. 
In the adult Lernea no trace of a nervous system could 
be made out, and certainly if present at all it is very much 
reduced. 
THe REPRODUCTIVE ORGANS. 
The reproductive organs of Lernawa, like those of 
Lepeophthewus, are bilaterally symmetrical. In the 
cyclops stage of the female (Plate V., fig. 1) the ovaries 
(o.) are pyriform organs lying on each side of the 
stomach. They are situated on the ventral surface near 
the posterior end of the cephalo-thorax. Mach oviduct 
(od.) arises near the posterior end, and courses posteriorly 
as a narrow tube. When it enters the genital segment it 
expands rapidly, ending in a large sac, the receptaculum 
seminis (s), communicating with the vulva (vu.). The 
oviduct has no distinet loops, and no cement gland is 
found. 
In the adult male (Plate LV., fig. 5) the testes (¢.) occupy 
the same positions as the ovaries in the female. The vasa 
deferentia are straight, narrow tubes coursing posteriorly 
and terminating in the sacs of the spermatophores. A 
cement gland is present, as in Lepeophtheirus. 
The ovary in the course of the metamorphosis under- 
goes great change of position. It is removed from the 
cephalo-thorax into the genital segment. It occupies a 
harrow region at the apex of the deep indentation (Plate 
V., figs. 4 and 5, 0.). The two ovaries have also practically 
fused together, no separation is visible in transverse sec- 
tion. The united ovaries are produced into horn-like pro- 
jections anteriorly and posteriorly (Plate V., fig. 5). The 
oviducts (od.) arise near the apex of the anterior horns, 
pass across the segment to its ventral surface, and then 
