Zoantharia— CUTRESS and PEQUEGNAT 
upper part and abruptly tapered below, for the 
greater part openly stratified and with large 
interstices and thick trabeculae (Fig. 8). Some 
of the interstices containing large cells with 
eosinophilic granules. 
Mesenteries. To 38 in number. In six of the 
largest polyps examined the following numbers 
of mesenteries were observed, 22 + 16 = 38 
(1), 20 + 14 = 34 (1), 19 + 13 = 32 (1), 
and 18 + 12 = 30 (3). Retractor muscles of 
the macrocnemes very weak, diffuse. Below the 
actinopharynx the macrocnemes are borne on 
high, longitudinal ridges projecting from the 
body wall into the coelenteron (Fig. 9). These 
ridges are thickenings in the column wall in- 
volving both the mesogloea and entoderm. All 
polyps sectioned were male and bore ripe testes. 
Actinopharynx. Smooth. Ectoderm with nu- 
merous acidophilic and few mucous gland 
cells. Siphonoglyph prominent, considerably 
longer than the actinopharynx. Hyposulcus in- 
distinct, same length as actinopharynx. 
Mesogloea. Of the scapus, 30 to 40 times the 
thickness of the entoderm, with a few scattered 
cells, few lacunae, and few or no cell islets; 
densely packed with sand throughout even into 
the ridges of the lower column upon which the 
macrocnemes are borne. Of the actinopharynx 
(siphonoglyph excepted), with rather numer- 
ous, large cells having a vacuolated cytoplasm. 
Of the oral disc, without cells. 
Ectoderm. Of the column, continuous, about 
one tenth the thickness of the mesogloea; con- 
taining sand, few mucous cells and numerous 
acidophilic gland cells. Of the oral disc, with 
few or no nematocysts but with numerous aci- 
dophilic gland cells especially around the mouth 
where the epithelium is unusually high. Among 
the acidophilic gland cells are cells (20 by 6 to 
7 g) containing nonstaining granules (.75 to 
1*5 g) 
Entoderm. Without zooxanthellae. Of the 
column, with numerous acidophilic gland cells. 
Of the actinopharynx and adjacent portions of 
macrocnemes, with large cells, similar to those 
of the ectoderm, containing large nonstaining 
granules. 
Cnidom. Spirocysts, of the tentacles, 10 to 12 
by 2 g, pyriform, very numerous. Microbasic 
b-mastigophores, of the tentacles, 15 by 2.5 to 
97 
Fig. 8. Transverse section of the marginal sphincter 
muscle of Epizoanthus induratum. Scale H .10 mm. 
3 g, few; of the actinopharynx, 18 to 22 by 3 g, 
numerous. Microbasic p-mastigophores, of the 
filaments, 15 to 19 by 5 g, numerous. Holotrichs, 
of the tentacles, 25 to 30 by 8 to 10 g, nu- 
merous; of the column (ectoderm), 20 to 28 
by 8 to 10 g, common; of the actinopharynx, 
30 by 10 g, few; of the filaments, 30 to 37 by 
10 to 11 g, numerous. 
DISCUSSION 
Epizoanthus induratum is a common species 
in the Corona del Mar area at depths of 75 feet 
and more. It has been observed to grow upon 
shale and the gorgonian Muricea calif ornica but 
is more frequently found on the former sub- 
strate. Those colonies on Muricea become estab- 
lished on the living gorgonian and encroach 
upon it in the same manner as has been de- 
scribed for Parazoanthus lucipcum. In reference 
to the firmness of this new Epizoanthus , caused 
by the dense incrustation of sand, the Latin ad- 
