Asterospicularia laurae — Utinomi 
193 
Fig. 2. Asterospicularia laurae n. gen. et n. sp.: a, transverse section of stomodaeal portion of polyp, X85; 
h, transverse section of lower portion of polyp, X135; c, longitudinal section of a part of coenenchyma with two 
polyps, X50; d, superficial view of a part of coenenchyma, showing the arrangement of spicules, X70. a-c from 
decalcified preparations and d from perfect specimen, (c coelenteron, ec ectoderm, en endoderm, / lacuna contain- 
ing spicules, namely spicular cavity, m mouth, mg compact portion of mesogloea, mg.s mesogloeal partition 
between spicular cavities, m.en mesogloeal cell of endodermal origin, ms mesentery, s solenia, t tentacle, t.en 
tentacular branch of coelenteron, zooxanthella.) 
mesogloea between the spicular cavities and 
then communicate with the neighboring 
cavities. Usually they have no lumen, but 
contain granular endodermal cells and zoo- 
xanthellae similar to those found in the 
coelentera (Fig. 2c). 
Zooxanthellae occur only in the endoderm, 
never in the ectoderm or in the mesogloea. 
They are most numerous in the tentacles and 
in the upper part of the coelentera between 
the mesenteries and solenia; they are found 
only sparsely in the deeper part. They are 
spherical and vary in diameter from 6 to S/i, 
the majority being 7.5 m- 
The stellate spicules, as mentioned above, 
occur only in the sharply circumscribed, 
rounded cavities of the honeycombed meso- 
gloea. The number of spicules contained in 
each cavity varies greatly according to the 
size of the cavity. The mesogloeal partitions 
between these cavities, which are very thin 
and compact and which appear to be a homo- 
geneous fibrous structure, contain no spicules 
at all (Fig. 2d). 
