132 THE VOYAGE OF H.M.S. CHALLENGER. 
white egg-mass on one of his ovigerous legs, and about one hour later both masses were 
present. 5 : 
The female genital openings.are a great deal larger than those of the male, and are of 
an ovate shape, and, as a rule, oviducts are totally wanting. I only observed them in 
the genus Colossendeis, where they have nearly the same course as the vasa deferentia. 
Nearly in the middle of the second coxal joint of the two hind legs a lateral branch 
arises from the ovarian coecum, which passes through the joint. The interior of this 
branch, which is the oviduct, is in immediate communication with the ovary, and during 
the breeding season the eggs are found penetrating the branch. While the ovarian cceca 
which penetrate the legs are lined only by connective tissue, the oviducts which 
begin at the dorsal side of the second coxal joint and run along the wall of the joint till 
they reach the opening on the ventral side, are lined by a coat of longitudinal muscle fibres. 
The female genital opening in this species is small and rather triangular.’ 
From the end of the oviduct which reaches the opening, distinct muscle fibres 
radiate, and are inserted round the opening on the inside of the chitinous wall of. 
the joint. A transverse section of the fourth jomt of the leg of a female Colossendeis— 
leptorhynchus is figured in fig. 16, Plate XVI. ; m is the ovarian ccecum which, as this 
specimen is by no means mature, is only of small dimensions; when in the breeding 
season, the whole central cavity (which in the figure is represented as empty) is filled 
with eggs ; it swells to such an extent as to fill up almost the whole cavity of the leg,-in 
so far as this is not occupied by the intestinal ccecum. As in the other species of 
Colossendeis, the eggs are extremely numerous and small. Each ovarian ege has a 
distinct germinal vesicle, which is placed almost exactly in the centre of the egg, and 
has, as a rule, one distinct and very glittering germinal spot. Among the older eggs, 
which are richly furnished with yelk, smaller ones are always observed whose protoplasm 
is almost quite transparent. Each ege is surrounded by a very thin membrane, which is 
a true ‘‘vitelline membrane” and adheres closely to the protoplasm of the egg. 
In the genus Nymphon, I have investigated the female genital organs of the follow- 
ing species :—Nymphon brevicaudatum, Miers ; N. brachyrhynchus, Hoek ; N.-robustum, 
Bell; NV. longicowa, Hoek; and N. hamatum, Hoek. I never observed the ovary in 
the body of these species, and always found at least a trace of it in the fourth joint of 
the leg (thigh). R 
When in an early stage.of development, the ovary is placed against and at the dorsal 
side of the intestinal ccecum which passes through the jomt. While the ripe ova, which 
‘are often very large (Pl. XVI. fig. 7 7, ripe ovum of Nymphon brevicaudatum, Miers), 
have a thin vitelline membrane as in the ovum of Colossendeis ; younger ova have often the 
1 In this species, as I have mentioned already (p. 63), the genital openings, both in males and females, are present 
only on the two hind legs ; at least in all the specimens at my disposition, I failed to observe them on the first two 
pairs of legs. However, ovarian cceca penetrate the first two pairs of legs as well as the two others. 
