Zoantharia — C utress and PEQUEGNAT 
99 
grains of sand occupying the main part of the 
mesogloea,” we find that the incrustation is 
largely in the very thick ectoderm and is only 
sparsely present in the mesogloea. This slight 
discrepancy is likely due, in Carlgren’s case, to 
the incrusting particles being carried into the 
mesogloea by a dull knife while sectioning. Al- 
though the polyps are small, they have a very 
thick column wall. The mesogloea is about five 
times as thick as the entoderm, and in turn the 
ectoderm is about two times as thick as the 
mesogloea. 
The description of the sphincter muscle given 
by Carlgren, "strong, broad, transversely strati- 
fied,” refers to the upper part only. He fails to 
mention that the sphincter tapers gradually to 
FIG. 10. Transverse section of the marginal sphinc- 
ter muscle of Epizoanthus gabrieli. The higher epi- 
thelium is entoderm. Scale M .10 mm. 
Fig. 11. Transverse section of a macro- and micro- 
cneme of Epizoanthus gabrieli. The large space in the 
column mesogloea is an artifact. Section taken from 
mid-column. Scale = .10 mm. 
a long tail which is more alveolar than stratified 
(Fig. 10). 
The mesenteries of the polyp cut by Carlgren 
number 30, but a second and slightly smaller 
one sectioned by us had 28. The mesogloeal 
lamellae of the mesenteries of E. grabrieli are 
greatly thickened near their attachment to the 
column wall ( Fig. 1 1 ) . In the case of the macro- 
cnemes, the thickened portion extends about 
half way to the filamental edge. The micro- 
cnemes, on the other hand, because they do not 
bear filaments, are entirely thick. In section, the 
microcnemes are about half the length of the 
thickened portion of the macrocnemes. The 
mesogloea of the thickened parts of the mesen- 
teries has much the same appearance as that of 
the column. The retractor muscles of the mes- 
enteries are very weak. 
REFERENCES 
Carlgren, Oskar H. 1898. Zoantharien. Er- 
gebnisse der Hamburger Magalhaensischen 
Sammelreise 1892, 1893. 1(4): 1-47, 1 pi., 
figs. 1-18. Hamburg. 
