336 EDITH M. PRATT. 
A few colonies confined in filtered sea water for seven days 
without food were fixed and preserved for comparison with 
well-fed colonies. 
Tue Mourn Disc. 
The histology of the mouth disc closely resembles that of 
the stomodzum (figs. 5 and 6), from which it differs in that 
the ectoderm is slightly thinner. It differs from that of the 
tentacles and general ectoderm in the scarcity of nemato- 
cysts, and in the presence of numerous granular gland cells 
similar to those of the stomodzum and mesenterial filaments. 
THe SToMODEUM. 
In Alcyonium, and in all other Alcyonaria, with the 
exception of Xenia, the function of the stomodzum has been 
believed to be limited to the conveyance of food material to 
the ccelenteron; it has therefore not been considered a 
portion of the digestive tract. 
The stomodzeum of zooids, which had been fed just before 
fixing and preserving, apparently contained no gland cells of 
any description, but in starved zooids the stomodeum showed 
a considerable number of gland cells with granular contents 
identical with cells occurring in the mouth disc and ventral 
mesenterial filaments (figs. 5 and 6). ‘These cells are very 
clearly indicated in sections from 2—4 in thickness, stained 
with iron brazilin, when the granules become intensely black. 
From the presence of gland cells in the stomodzeum of 
starved zooids, and their apparent absence in recently fed 
zooids, it may be assumed that the food has received a 
secretion from the cells, in its passage through the stomo- 
deum. (Reference is again made to the subject of secretion 
in connection with the description of the gland cells of the 
mesenterial filaments, pp. 342—345.) 
appears to agree with C. viridis in every other respect, however, it cannot 
be regarded as a distinct species. 
