134 SIDNEY F. HARMER. 
possible that the earlier processes of the development would be 
more easily made out in the second brood than in the first 
brood. 
General Conclusions. 
The only genus with which Lichenopora can be compared, 
as regards the embryonic development, is Crisia. In no 
other case have the early processes been described at all. 
In Crisia certain zocecia take on the character of ovicells. 
A polypide-bud makes its appearance in the young ovicell 
while the latter is at the growing-point of the branch, and is 
not externally marked out in any way as an ovicell. The bud 
becomes connected with an egg, and develops a tentacle-sheath 
which shows it to be a modified polypide. The greater part of 
the bud, however, forms what may now, on the analogy of 
Lichenopora, be termed an embryophore ; and in this struc- 
ture the embryo develops and undergoes its fission. There is 
no fertile brown body; and the ovicell is recognisable exter- 
nally as a structure which looks like a zocecium that has been 
inflated. 
While the ovicell of Crisia is thus clearly a modified 
zocecium, which develops a polypide-bud in the ordinary way 
at the growing-point, the morphology of the ovicell of Lichen- 
Opora is more obscure. There is no doubt that the embryo is 
formed in a zocecium; but it is formed in a fully developed 
zocecium which probably is normally tenanted by two succes- 
sive polypides. Each of these becomes a brown body in turn, 
the second brown body fusing with the first to form the charac- 
teristic fertile brown body. The exact origin of the embryo- 
phore is not as clear as it was in Crisia; but there is nothing 
to show that it is morphologically a bud. The later history is, 
however, not dissimilar. The embryophore becomes vacuolated, 
and in the vacuoles so formed the secondary embryos are later 
found. Certain differences in the details of the embryonic 
fission have already been pointed out. The fertile zocecium 
becomes occluded, and its cavity then becomes continuous with 
a series of alveoli or interzocecial spaces, which occur between 
