202 
ZOOPHYTA HELIANTHOIDA. 
ment.”* The supposition readily explains some facts which have 
given rise to an opinion of their viviparous generation, for the 
young will be born alive if the easy admission is made that some 
of the ova may have their egress delayed until they have passed 
through their first stages of evolution. That many ova, and pro- 
bably by much the greater number, escape previously to this is 
now well ascertained. 
Mr Teale’s description of the ovaries varies also from Spix’s, 
and is very accurate. In Actinia gemmacea he tells us they 
form <c elongated masses attached along the inner border of 
most of the leaflets. Each ovary is composed of several hori- 
zontal folds or plaits, which, when unfolded, show this structure 
to be about three times the length it assumes when attached to 
the leaflet. By carefully spreading out these folds, the ovary, 
with the assistance of a lens, is seen to consist of two very de- 
licate layers of membrane, enveloping a closely compacted layer 
of ova. After enveloping the ova, the membranous layers are 
placed in apposition, and form a kind of mesentery, by which 
the ovary is attached to the internal border of the leaflet. The 
two layers afterwards separate to pass one on each side of the 
leaflet, thereby lining the interseptal spaces from which this 
membranous investment is prolonged into the tentacula, as well 
as into the cavities within the structure of the lip and mouth. 
At the summits of the tentacula, and of the tubular eminences 
of the lip, the membrane becomes continuous with the common 
integument, whilst at the inferior part of the interseptal spaces 
it is continuous with the digestive sac. The breadth of the 
ovaries is nearly uniform from the top to the bottom. Some ir- 
regularities are occasionally observed in their attachment to the 
leaflets. Sometimes one leaflet supports two ovaries, and not 
unfrequently two neighbouring ovaries are continuous with each 
other at their inferior extremities.” -f- 
The period of propagation is probably, in most Helianthoida, 
not limited to any particular season. According to the obser- 
vations of Cavolini the Caryophyllia matures its ova in spring ; 
and it is only at this season that I have found the Lucernarise on 
* Leeds Phil, and Lit. Soc. Trans, i. 111. f Lib. supra cit. p. 104. 
