56 kecords of the Indian Museum. [VoL. XII, 
being translucent and vacuolated, having indeed the same appear- 
ance as the cells of the hydrosome. It has been mentioned that 
the change in the appearance of the cells at the base of the hydro- 
some is characteristic and sudden. The junction between the 
translucent end of the blastostyle and the opaque proximal por- 
tion has exactly the same appearance (plate vi, fig. 1). The trans- 
lucent end of the blastostyle therefore perhaps represents a reduced 
hydrosome. Be that as it may, it is a conspicuous feature of 
the gonosome visible from first to last, forming in the later stages 
a kind of lid closing in the gonotheca. It may be referred to as 
the operculum. 
The medusae arise from buds which spring from the stem of 
the blastostyle below the operculum, They appear to arise in the 
usual manner by the sinking in of an entocodon. A conspicuous 
feature of the development is the early formation of four large 
lappets, placed radially on the margin of the bell. Upon these 
the tentacles appear at a later stage. 
At the time when the first bud appears upon the blastostyle, 
it is evident that the cavity of the operculum is in open communi- 
cation with the cavity of the cylindrical stem But later when 
the development of the medusae is more advanced, the stem of 
the blastostyle becomes flattened out and can scarcely be traced. 
But even at a comparatively late stage the endodermal cavity of 
the two growing medusae may be seen communicating with one 
another through the cavity of the blastostyle. One specimen 
shows a similar communication between the cavity of a medusa 
and that of the operculum. Though much compressed and 
rendered inconspicuous by the growing medusae, it is probable 
that the stem of the blastostyle preserves its status until the end. 
Thus, in the oldest gonosome met with, the stem of the blastostyle 
can plainly be seen between the two medusae, and its communica- 
tion with the cavity of the operculum may be inferred owing to 
an interesting circumstance. The cavity of the stem of the blasto- 
style contains a number of irregular nucleated cells which have 
much the appearance of phagocytes and the same kind of cells are 
to be seen in the cavity of the operculum. This fact indicates 
that the communication between the stem of the blastostyle and 
the operculum persists to a late stage. Little seems to be known 
of phagocytesis among the Coelenterata but it is unlikely that a 
process so general in the animal kingdom should not occur in this 
group. It is possible that the presence of these cells, which, as 
I have said, have the appearance of phagocytes, indicate the 
approaching dissolution of the distal part of the gonosome and the 
liberation of the mature medusa. 
The Gonotheca. 
In the early stages of its development the gonosome is com- 
pletely enclosed by a delicate perisarc. The later history of this 
layer, as to how and when it allows the liberation of the medusae, 
was not ascertained. 
