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narrow neck towards the summit of the blastostyle, but I failed in 
my attempts to trace its connections beyond this point. 
The extra-capsular ova, with their investing sacs, and the surround- 
ing coecal tubes, would thus lie entirely exposed, were it not that 
they are protected by the three leaflets already mentioned as con- 
stituting the trihedral portion of the gonophore. These leaflets are 
given off from the external surface of the oval portion, or proper cap- 
sule, near its summit, and, being in contact by their edges, completely 
enclose a space which is occupied by the structures just described. 
Though I have not succeeded in discovering the exact connection 
between the common extra-capsular ovigerous sac and the structures 
in the interior of the capsule, nor the precise mode by which the 
ova gain access to it, I have no hesitation in viewing it as a true 
acrocyst in which the ova undergo a further development, previously 
to their liberation as free embryos. 
In the following three species, the gonophores contained in all the 
specimens I examined, medusae, and never sporosacs. These 
medusae have been more or less investigated by Van Beneden, Gegen- 
baur, Dalyell, Gosse, Hincks, Wright, and other observers, and I 
here give the results of my owm independent examinations, as partly 
confirmatory of the observations of these naturalists, and as partly 
supplementary to them. 
Eudendrium ramosum , Van Beneden. 
I obtained this species in fine condition, attached to an old buoy 
in the harbour of Derryquin, on the Kenmare Biver, County Kerry, 
in September 1858. 
The gonophores are simple, and are borne upon the ultimate ra- 
muli, where they may be seen springing from the upper and lateral 
surfaces of the ramulus along its whole length. They are obovate, or 
fig-shaped bodies, each supported on a distinct peduncle, and in- 
vested by a delicate chitinous extension of the polypary. 
When the gonophore reaches maturity, the ectotheque and its 
chitinous investment become ruptured at the summit, to allow of the 
escape of the medusa as an independent free-swimming zooid. 
The medusa, on escaping, is provided with a deep umbrella, 
which measures about ^ of an inch across its base, where it is fur- 
nished wfith a well-developed velum. 
