442 Happon—The Actiniaria of Torres Straits. 
AULACTINIA, Verr. 
‘‘ Bunodide, with the upper portion of the column provided with longitudinal 
rows of verruce, the lower portion being smooth. The margin forms a more or 
less distinct collar, and the tentacles are polycyclic and entacmzous. The six 
pairs of mesenteries of the first cycle are alone perfect (?).” 
I have adopted MeMurrich’s (1889, Journ. Morph., p. 27) definition of this 
genus, but I have queried the last statement. I have no doubt that this is true of the 
type species, and it may be diagnostic of the genus; but rather than make a new 
genus of the Torres Straits species, I have ventured to include in Aulactinia a 
species which has more than six pairs of perfect mesenteries. Quite possibly the 
two species will subsequently be dissociated. 
Externally Aulactinia differs from Bunodes, in having suckers in the upper 
portion of the column only, whereas the latter genus is more or less uniformly 
tuberculated ; Leiotealia is quite smooth. The new genus, Ixalactis, is character- 
ised by its peculiar tentacles, and in having the upper portion of the column 
verrucate and the lower smooth. Carlgren (1893, p. 58) confirms the obser- 
vations of Gosse (1860, Actin. Brit., p. 209), the brothers Dixon (Proc. R. D. S., 
1889, p. 820, A. M. N. H., January, 1890, p. 66), and J. T. Cunningham 
(Journ. Mar. Biol. Assoc. 1889, p. 205), on the quinary symmetry of Urticina 
(Tealia); the column of this genus is verrucate. For the present I follow the 
general custom of leaving Urticina in the Bunodide. 
Gyractis has a perfect sex-radial symmetry : it may not belong to this family. 
Aulactinia Gelam (H. &8.). 
Condylactis Gelam, Hadd. and Shackl., 1893, Proce. R.D.S. vim, p. 1238. 
(PI XXT fig. 12: PI XXOVa, fies: 6573) 
Form.—Column smooth, expanded at capitulum, which is furnished with 
suckers ; disk feebly retractile; mouth circular, with two or three gonidial 
grooves; tentacles long, in six or seven cycles, from about 192 to 240 in number. 
Colour.—Column red-lead colour below, passing into creamy yellow above; 
underside of capitulum grey, with pale suckers; (a) disk and tentacles olive 
brown ; mouth green; tentacles with a greenish contour, and tipped with 
magenta; (2) disk grey; tentacles dark grey, with a buff sheen. 
Dimensions.—Height of column, 150 mm. (6in.); diameter, 44 mm. (17 in.); 
diameter of oral disk, 95-115 mm. (33-44 in.); length of tentacles, 50 mm. 
(2 in.) ; diameter of corona, 180 mm. (7 in.). 
