Zoantharia — CUTRESS and PEQUEGNAT 
thick sticky slime upon stimulation or when re- 
moved from the water. 
DESCRIPTION: Size. In life the largest polyps 
are 15 mm. long and 3.5 mm. in diameter. In 
the preserved semiexpanded condition the larg- 
est polyps of the holotype are about 4 mm. long 
and 2.5 mm. in diameter. The holotype colony 
almost completely covers the numerous branches 
of a 20 cm. gorgonian. 
External Aspects. P. lucificum occurs at depths 
of 40 to 90 feet and is found on about 5 per cent 
of the Muricea calif ornica in the Corona del Mar 
area. Whole colony brilliantly bioluminescent 
and secreting copious quantities of slime. Coe- 
nenchyme thin and incrusting, for the most part 
completely investing the branches of the gor- 
gonian. Polyps numerous, moderately crowded, 
not arranged in a definite pattern. Scapus thin- 
walled, allowing the insertions of the mesen- 
teries to show through. Ridges of the scapulus 
numbering to 17, indistinct in contracted polyps 
but distinct in expanded ones. On some of the 
well-expanded polyps the ridges of the scapulus 
resemble incrusted marginal vesicles. Between 
each ridge (just below each outer tentacle) there 
is a distinct V-shaped area devoid of incrusta- 
tion. Coenenchyme and scapus surface sparsely 
incrusted with very fine sand, shell, occasional 
sponge spicules and foraminifers. Tentacles ar- 
ranged in two cycles, moderately long, to 30 in 
number. Color of living specimens is bright 
yellow with a distinct orange ring around the 
mouth which extends into the actinopharynx 
and along the macrocnemes near the gonads. 
Sphincter . In the entoderm, weak, made up of 
15 to 18 low simple plaits, diffuse (Fig. 2). 
Mesenteries. To 30 in number. In the 15 
polyps examined the following numbers of mes- 
enteries were observed: (25) 8, (27) 3, (28) 
3, (30) 1. The polyp with 30 mesenteries had 
17 macrocnemes and 13 microcnemes. The fila- 
ments are attached throughout their length to 
the macrocnemes and extend about three-fourths 
of the distance from the actinopharynx to the 
base. The scanty gonads are borne on the mac- 
rocnemes just below the actinopharynx. Re- 
tractor muscles of the macrocnemes very weak, 
diffuse (Fig. 3). Microcnemes scarcely extend- 
ing above the column entoderm. The polyps of 
the holotype are female and those of the para- 
91 
Fig. 2. Transverse section of the marginal sphincter 
muscle of Parazoanthus lucificum. Scale = .10 mm. 
type, male. The gonads are ripe during June, 
July, and August. The larvae are retained within 
the body until they are well developed and are 
commonly observable in the lumens of the ten- 
tacles. The larva is of the zoanthella type. 
Actinopharynx. Longitudinally corrugated. 
Siphonoglyph shallow but distinct. Hyposulcus 
indistinct, only slightly shorter than the siphono- 
glyph. Ectoderm without mucous or eosinophilic 
gland cells. 
Mesogloea. With an extensive encircling 
sinus which is lined with cells similar to those 
of the ectoderm, with lacunae which do not 
contain cells, and with few cell islets. Contain- 
ing very little of the incrusting material. 
Ectoderm. Continuous, about one half the 
thickness of the mesogloea and containing most 
of the sparse incrusting material. With no 
mucous cells but on the surface and in some 
parts of the encircling sinus with a diffusely dis- 
tributed nonparticulate material (probably the 
slime) which stains like mucus with hema- 
toxylin. 
Entoderm. Without zooxanthellae. 
Cnidom. Spirocysts, of the tentacles, 18 to 22 
by 3 i u, very numerous. Microbasic b-mastigo- 
