LIMNOCODIUM (CRASPEDACUSTES) SOWERBII. 369 
I have examined^ I have not found one female. Yet females, or 
egg-bearing forms, are there. 
"when I first received specimens of the Medusa from Mr. 
Sowerby, he imparted to me his conviction that young Medusae 
were being hatched in the glass jar in his sitting-room, which 
contained a number of full-grown specimens. He inferred this 
from the fact that among these large specimens which he had 
introduced into the jar a number of minute specimens made 
their appearance after the lapse of three or four days. On a 
subsequent occasion Mr. Sowerby again drew my attention to 
these minute Medusae, and enabled me to examine a number of 
them. 
Had I been preoccupied with the notion that Limnocodium 
must have a hydriform trophosome, I might perhaps have neg- 
lected the opportunity of examining these minute forms. But as 
I had come to the conclusion, on anatomical grounds, that Lim- 
nocodium is one of the Tracho medusae, I was quite prepared, 
when Mr. Sowerby for the second time mentioned these minute 
Medusae, to find very minute Limnocodia hatched from eggs in 
the vessels in which the adults were kept. 
The youngest specimen which I have at present examined 
measured only one thirtieth of an inch in diameter, and I have 
examined others very little larger. 
They agree in a very striking way with the embryo of 
Geryonia hastata, figured by Metschnikow in the ^ Zeitsch. fiir 
wiss. Zoologie,’ Bd. xxiv, pi. ii, figs. 13, 15. There is no pos- 
sibility of doubting that these embyros were developed from eggs, 
just as are those of Geryonia, Cunina, and Higinopsis. 
The smallest embryo (woodcut, fig. 4) was of a slightly de- 
pressed, nearly spherical, form. It exhibited that very striking 
separation of the ectoderm from the endoderm layer which is seen 
in the similar embryo of Geryonia. Pour perradial tentacles, very 
short and stump-like, were sprouting at a little distance from one 
depressed pole of the sphere. Between these, rudiments of four 
others were seen. The external ectodermal layer was unbroken 
and not invaginated at any part of the sphere. Yet within could 
be seen the subumbrellar cavity, the manubrium with its mouth, 
the quadrangular stomach, and the four radiating canals. 
The ectoderm was, it is very strange to say, continued across 
the mouth of the umbrella, so as to close in the subumbrellar 
space. Were this covering to be ruptured centrally the sub- 
umbrellar cavity would be found ready formed, with dependent 
manubrium and mouth. The ectodermal lid thus centrally per- 
forated would very readily become the velum. 
I am at this moment unable to say whether this is the 
mode of development, since in specimens a little larger with 
