88 
CHARLES L. BOULENGER. 
nematocysts of the batteries ; moreover, the slightly broader 
basal ends with the nematoblasts are directed away from the 
umbrella edge and towards the distal extremities of the 
tentacles. 
The above-described orientation, which is even more con- 
Text-fig. 1. 
Surface view of part of a large tentacle, showing the polygonal 
ectoderm cells and two rings of stinging-cell batteries. Below 
the large transparent cells are a number of migrating stinging- 
cells, all moving in the same direction towards the more distal 
parts of the tentacle ; in one place (a?) they can be seen coming 
together to form a battery, cnid. Nematoblast of a migrating 
stinging-cell. ect. Ectoderm cell. nem. b. Battery of stinging- 
cells. st. c. Migrating stinging-cell. The arrow shows the 
direction in which the stinging-cells are moving. (Semi- dia- 
grammatic.) 
spicuous in longitudinal sections of the tentacles (PI. 15, 
fig. 2), shows that the stinging-cells of the tentacle-bases are 
