Happon—The Actiniaria of Torres Straits. 485 
Genus.—HETERODACTYLA, Ehr., 1834. 
Thalassianthide, in which the oral disk is of much greater diameter than the 
column ; the margin of the disk may be thrown into irregular and inconstant large 
folds; the peristome is bare, but the greater portion of the oral disk is covered 
with smooth tufted tentacles; at the margin is an interrupted series of tentacles 
bearing urticating spheres. 
A. Hemprichii, Ehy. H. hypnoides, 8.-K. 
Heterodactyla Hemprichii, Ehr. 
Heterodactyla Hemprichii, Ehrenberg, 1834, Korallth. des Rothen Meeres, p. 42; 
Milne Edwards, 1857, Hist. Nat. Cor. i1., p. 298; 
Klunzinger, 1877, Korallth. des Rothen Meeres, 
p- 90, pl. 7, fig. 1; Andres, 1884, ‘Le Attinie,” 
p. 298; Saville-Kent, 1893, ‘ Barrier Reef,” p. 147, 
chromo pl. iii, fig. 3. 
Form.—Column cylindrical, short, with indistinct verruce ; oral disk much 
wider than column, so that the polyp is salver-shaped, the edges often thrown into 
lobes. The central fifth of the disk is bare, but the remainder is covered with 
numerous short tentacles, which bear a variable number (up to a dozen or so) of 
filaments disposed irregularly at various heights along each tentacle. Along the 
border are short tentacles bearing a small number (about six, never more than 
ten) of spherical, pedunculated tubercles, ‘‘ nematospheres”; occasionally the 
tentacles which bear the nematospheres are also provided with terminal filaments. 
Saville-Kent describes the tentacles as ‘‘ more or less distinctly pinnate, developed 
singly or in interrupted rows near the centre of the disk, becoming more thickly 
massed as they approach the peripheral border.” 
Colour.—Column pale yellowish red, the upper portion spotted with violet ; 
margin greyish; disk greyish blue, with brown streaks externally; tentacles 
greyish red, with white tips; nematospheres violet, with a green spot (Klunz.). 
Column pale pink, with vertical rows of carmine spots; oral disk light olive 
brown peripherally ; pale lemon yellow in centre, and a variegated mixture of 
the two between ; tentacles transparent lemon yellow, with an olive brown core; 
nematospheres brilliant translucent violet, with a vivid emerald green apical spot. 
In one specimen small patches of the tentacles were entirely lemon-yellow 
(S.-Kent). 
