438 Happon—The Actiniaria of Torres Straits. 
Hoplophoria cincta (H. & S.) 
Viatriz cincta, Hadd. and Shackl., 1893; Proc. R.D.S., vim. p. 127. 
(Pl. XXIII, figs. 11-15.) 
Form.—Tissues very delicate, column short, cylindrical, with a very extensile 
and variable capitulum ; at the junction of the capitulum with the scapus are at 
least six club-shaped prolongations which may bear tubercles on their aboral 
aspect; sometimes the capitulum is produced as a broad, thin, horizontal rim 
round the top of the column, from the margin of which project the club-shaped 
organs. Tentacles of moderate length in three cycles (12 + 12 + 24 = 48). 
Colour.—Kctoderm colourless; but the endoderm everywhere shines through 
with a reddish-brown colour; processes with white ends; tubercles, brilliant 
green. 
Dimensions.—Height of column, 6 mm.; total expanse of capitular rim, about 
15 mm. 
Habitat.—Surface of reef, Mabuiag, October, 1888. 
This is probably an immature form; the specific name is derived from the 
girdle-like appearance of the capitular rim, beset, as it were, with bosses of 
emeralds. It appears to be allied to Hoplophoria coralligens, Wils.* Professor 
M‘Murrich has, however, informed me that this species is Viatrix globulifera 
(Duch.); but I must confess to seeing but little resemblance between the figures 
given by Wilson and by Duchassaing and Michelotti.t If Dr. Wilson’s species is 
a Viatriz, this must be also placed in that genus. 
Only one immature specimen was obtained. 
Body-wall.—Thin, especially the ectoderm and mesoglea. The ectoderm 
has no distinct muscular layer. The ectoderm, and the acrorhagi, like that 
of the tentacles, contain very numerous, long, narrow nematocysts and gland 
cells. 
The endoderm is closely packed with zooxanthellae, which doubtless give to it 
its distinctive colour. A feeble endodermal muscle layer is present, which is much 
more marked in the proximal portion of the acrorhagi. 
Sphincter muscle.—I cannot be certain that there is any sphincter at all. 
* A. VY. Wilson ‘On a New Actinia, Hoplophoria coralligens.’ Studies Biol. Lab. Johns Hopkins 
Univ. rv. Pl. xl. 
+ ‘‘ Mémoire sur les Coralliaires des Antilles.” Mem. Reale Accad. Torino (2) xx. 1860. PI. vi. 
figs. 15, 16. 
