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PACIFIC SCIENCE, VoL V, April, 1951 
are mostly circular or oval to oblong in out- 
line, as shown in Figures 2a-d. Each of these 
lacunae is beset with 1 to 8, rarely up to 10, 
stellate spicules, the number varying accord- 
ing to the size of each lacuna. In most other 
alcyonarians, however, the mesogloea is more 
or less compact and is beset, either densely 
or loosely, with spicules. Each spicule origi- 
nates from a single scleroblast of ectodermal 
origin, so that the space or cavity for a spicule 
is closely fitted to the form of the spicule 
contained in it (Koch, 1878; Hickson, 1895; 
Woodland, 1905; Bock, 1938). In this 
alcyonarian, the spicular cavity is constant 
in form, irrespective of the number of spicules 
contained. Though I made no actual ob- 
servations on the development of the spicules, 
there is no evidence in my preparations of the 
presence of a number of spicules in a single 
cavity originating from a single spicule- 
forming cell or scleroblast. 
The body wall of the anthocodia is com- 
posed of three layers — an outer rather thick 
ectodermal layer, a very thick mesogloeal 
layer, and an inner endodermal layer. Of these, 
the mesogloea is divided into two layers — 
the outer layer (with large lacunae containing 
spicules) which lines the epidermis and the 
inner layer with smaller empty lacunae (Fig. 
2d). The inner layer surrounding the co- 
elenteric cavity forms a homogeneous fleshy 
mass scattered with free mesogloeal cells 
which are endodermal in origin. These cells 
are rather large, measuring 4 to 10/x in dia- 
meter, and contain darkly stained oval or 
spindle-shaped nuclei. It is highly probable 
that these mesogloeal cells of endodermal 
origin are the direct continuations of the 
endodermal cell-strings or canals (i. e., sole- 
nia) or their derivatives. Their function is 
probably to give nutrition to, and to perform 
excretion from, the mesogloea, as suggested 
by Hickson (1895), Pratt (1903, 1905), Bock 
(1938), and Gohar (1940^). No mesogloeal 
cell of ectodermal origin suggesting a nerve 
plexus could be traced. 
The epidermis is coated with a thin outer 
cuticle and is rather thick. It occupies the 
area between the outer cuticle and the outer 
layer of the spicular cavities of mesogloea. 
Its basal lining is indistinct, since the outer 
contour of the superficial mesogloea con- 
taining the larger spicular cavities is very 
irregular. Thus the thickness of the epidermis 
is considerably varied in different parts of the 
body. As far as I have observed on the decal- 
cified preparations, the epidermis appears to 
be formed of more than one layer of ecto- 
dermal cells. All these cells are irregularly 
arranged, and the ordinary supporting and 
interstitial cell layers cannot be distinguished. 
Also I have seen no nematocysts or mucous 
gland cells in the epidermis. 
The mouth leads into a very short stomo- 
daeum which penetrates deep into the coelen- 
teron. The stomodaeum is lined internally by 
a thick columnar epithelium and is provided 
on the ventral side with the siphonoglyphe. 
In the stomodaeal region, the mesenteries 
have thickenings (the so-called muscle ban- 
ners) on the ventral side situated closer to the 
stomodaeum than to the coelenteric wall. 
Further details of the structure of the mesen- 
teric filaments could not be traced. All the 
mesenteries appear very thin and run straight 
from the lower end of the stomodaeum down 
to the bottom of the coelenteron. 
The endodermal cells of the coelenteric and 
tentacular cavities, together with zooxanthel- 
lae contained within them, are very loosely 
packed in the whole space and form an unde- 
fined mass. The boundaries between the 
endodermal cells are, however, slightly visi- 
ble. Apparently these cells do not form any 
ordinary epithelial lining on the coelenteric 
walls such as is found commonly in ordinary 
coelenterates. In the lower part of the coelen- 
teron, however, the endodermal cells are 
situated close to the wall and mesenteries. 
The internal canal system is not so well 
developed as in the Alcyoniidae. The endo- 
dermal cell- strings or canals are seen most 
clearly near the surface of the coenenchyma; 
they take a sinuous or zigzag course in the 
