THE DIGESTIVE ORGANS OF THE ALCYONARIA. 387 
In the presence of gland cells in the stomodeum Alcyo- 
nium resembles Xenia. The cells, however, differ from 
those described by Ashworth, 1898, in that genus, in form 
and in their granular character. In Xenia they are swollen, 
flask-shaped, and, according to Ashworth, give rise to a 
mucous secretion. As I have observed both mucous and 
granular gland cells in the stomodeum of every species of 
Sarcophytum (fig. 5), Lobophytum, and Sclerophytum 
(fig. 6) which I have examined they doubtless occur through- 
out the family. 
. Gland cells occur in the stomodzeum of several Zoantharia, 
and have been described in Flabellum by Stanley Gardiner 
(1902), and in Meandrina by Duerden (1903). The cells 
differ slightly in shape and size in the two groups of Coelen- 
trates, but. doubtless have the same function. 
In several members of the Zoantharia the stomodzal ecto- 
derm is raised into ridges at the insertion of the mesenteries, 
where in Meandrina it differs in character from the thinner 
ectoderm between the ridges. In all the members of the 
Alcyonaria which I have had the opportunity of examining, 
the ectoderm of the stomodzum, though usually convoluted 
in the preserved condition is similar in character and of 
apparent uniform thickness throughout, no thickenings being 
apparent at the insertion of the mesenteries. 
The stomodeal ectoderm of Alcyonium, Sarcophytum 
(fig. 5), Lobophytum, and Sclerophytum (fig. 6) is made 
up histologically of the following elemental cells, which occur 
in varying proportions, the relative abundance of granular 
gland cells being in many cases dependent on the condition 
of the zooids with regard to the supply of food material : 
(a) Granular gland cells, usually irregular in shape, and 
containing a varying number of rounded granules, which 
become intensely black when subjected to stains containing 
iron. ‘These cells are histologically identical with the 
granular gland cells of the mouth disc and mesenterial 
filaments. ‘Their function is discussed on pp. 343—3845. 
(6) Mucous gland cells with deeply staining nuclei. 
