Happon—The Actiniaria of Torres Straits. 421 
tentacles, with a grayish-brown core and a green satin-like sheen, some- 
times with a pale ring near the tip, or with the tip of a paler and brighter 
green. 
Dimensions —Height of column about 38 mm.; diameter of oral disk about 
46 mm. 
Habitat.—Reef, Waier (Murray Islands). 
The ectoderm of the body-wall not well preserved; but, where present, appears 
to consist of granular and indistinct cells. The mesogleea is thick, and contains 
numerous darkly-stained nuclei similar to those in the endoderm ; they are 
generally surrounded by a narrow zone of mesoglcea, which is less deeply 
stained than the neighbouring mesoglea. 
The endodermal sphincter muscle (Pl. xxv, fig. 6) is very feeble, and 
consists of a group of five or six plaits, some of which are slightly 
branched. 
Tentacles—The nuclei of the ectoderm cells are diffusely scattered. The 
nematocysts are very distinct. The muscle layer is well developed. The endoderm 
is crowded with zooxanthelle. 
There are about thirty-three pairs of non-directive mesenteries in the specimen 
investigated, many of which are perfect. The arrangement of the mesenteries is 
extremely irregular, and no symmetry could be discovered. There are four 
pairs of directive mesenteries, of which one pair is more strongly developed 
than the others. There are four cesophageal grooves corresponding to the 
directives, and their cesophageal lappets extend nearly to the base of the 
coelenteron. 
The longitudinal muscles of the mesenteries are well developed; the meso- 
gloeal folds are slender, and ramify but little; the muscle-fibres nearer the wall are 
less developed. (PI. xxvr., fig. 7.) Basal muscles on small pennons, on opposite 
side of mesentery to the longitudinal muscles, are present in the larger mesen- 
teries. The mesogloea of the mesenteries is thick, and contains nuclei similar to 
those in the body-wall. The mesenterial filaments are much twisted and coiled ; 
thread-cells and clear oval cells present among the columnar cells; the latter 
contain deeply-staining nuclei. 
No gonads occurred in the specimen examined. 
