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PACIFIC SCIENCE, Vol. XIV, April I960 
off shore at a depth of 75 feet. Collected by 
Willis E. Pequegnat, November 6, 1958. Colony 
incrusting the base and lower portions of a 
Muricea californica which was attached to a 
shale reef. 
Paratype, U.S. Nat. Mus. Cat. No. 51055, one 
colony of about 20 polyps. From Corona del 
Mar, California, one half mile off shore at a 
depth of 75 feet. Collected by Willis E. Peque- 
gnat, November 6, 1958. Colony incrusting a 
piece of shale. 
Paratype, U.S. Nat. Mus. Cat. No. 51058, sev- 
eral fragments of a colony with a total of about 
100 polyps. From l l A miles S. E. of Corona del 
Mar, California, at a depth of 75 feet. Collected 
by Willis E, Pequegnat, November 26, 1958. 
Colony incrusting a piece of shale. 
DIAGNOSIS: Colonies large, consisting of nu- 
merous, rather widely separated polyps. Coe- 
nenchyme moderately thick, incrusting, greatly 
expanded and heavily impregnated with fine 
sand. Scapus thick-walled, heavily impregnated 
FIG. 7. Epizoanthus induratum. Paratype. X 1-5. 
with fine sand. Ridges of the scapulus to 22 in 
number, indistinct in contracted polyps but 
prominent in expanded ones. Tentacles and mes- 
enteries to 38 in number. Marginal sphincter 
muscle in the mesogloea moderately strong. 
Mesogloea thick, with few single cells except in 
the actinopharynx, few lacunae, and few or no 
cell islets. The species grows principally upon 
shale but may occasionally be found on the gor- 
gonian Muricea californica, is bioluminescent 
and pale salmon in color. 
DESCRIPTION: Size. Of large expanded liv- 
ing polyps, length 7 mm., diameter of oral disc 
6 mm., length of tentacles 7 mm. In a preserved, 
semicontracted state the polyps vary in length 
and diameter from 1 by 1.5 mm. to 5 by 4 mm. 
The holotype colony covers the base ( about 5 by 
8 cm.) of a Muricea californica and extends 
along several of the main branches of the gor- 
gonian for a distance of about 8 cm. 
External Aspects. Epizoanthus induratum oc- 
curs on shale and the gorgonian Muricea cali- 
fornica at 75 feet or more. It is an abundant 
species in the Corona del Mar area and has been 
observed to form colonies 10 square meters or 
more on the shale bottom. The species is firm, 
rough to the touch and bioluminescent. Coe- 
nenchyme incrusting, moderately thick, very 
much expanded, and heavily incrusted with fine 
silicious sand. Polyps numerous, those of col- 
onies growing upon shale rather widely sepa- 
rated one from the other but those of colonies 
growing upon gorgonians closer together. Polyps 
randomly arranged and unequal in size (small 
ones interspersed with large ones ) . Some of the 
polyps of the preserved specimens are high and 
free while others, presumably more contracted, 
scarcely extend above the surrounding coe- 
nenchyme ( Fig. 7 ) . Scapus thick-walled, heavily 
incrusted with fine silicious sand. Ridges of the 
scapulus prominent in expanded polyps but in- 
distinct in contracted ones, to 22 in number. 
Scapulus devoid of incrustation except for the 
ridges which are heavily incrusted. Tentacles 
long, to 38 in number. Color in life pale sal- 
mon, tentacles unmarked, mouth edged with 
white and immediately peripheral to this a ring 
of yellow. 
Sphincter. Moderately strong, lying in the 
outer portion of the mesogloea, broadest in its 
