Hapvpon—The Actiniaria of Torres Straits. 445 
The mesenteries, so far as I can make out, consist of 192 pairs, arranged in the 
usual symmetry of six. There are two gonidial grooves. 
The position and character of the sphincter muscle are shown in PI. xxvutt., 
figs. 8,9. ‘There is a long central stem of mesogloea, with root-like branches 
along the greater part of its length on both sides. 
LEIOTEALIA, Hertw. 
Bunodide, with the column smooth, and without spherules, but with longi- 
tudinal furrows corresponding to the insertion of the mesenteries. Tentacles 
of equal size arranged in several cycles. Twelve pairs of perfect mesenteries. 
Body constricted by a special circular diffuse endodermal muscle. 
URTICINA, Ehr. (Tealia, Gosse). 
Bunodidz, with the column provided with adhesive warts or suckers 
arranged in vertical series, suckers largest above. Capitular margin forming a 
parapet, separated from the tentacles by a broad fosse. Tentacles numerous, 
in decimal cycles, short or of moderate length and of uniform size. At least 
twenty pairs of perfect mesenteries. 
GYRACTIS, Boy. 
Bunodidz (?), with a perfect radial symmetry, all the pairs of mesenteries 
have their longitudinal muscles on the sides facing one another, ze., in the 
endoceels; new mesenteries are developed in the exoccels. Mouth circular, no 
siphonoglyphes present. Circumscribed endodermal sphincter muscle. 
Li. excavata, Bov. EL. pallida, Boy. 
Boverl (Das Genus Gyractis, eine radial-symmetrische Actinienform, Zool. 
Jahresbr., vil., 1893, p. 241) proposes the tribe Holactiniz for the reception of 
this new Sinhalese genus. As the variability, and even the absence of direce- 
tives in various groups or genera of Actiniaria is now being recognised, it is doubtful 
how far it is wise to make this a primary character. As previously mentioned, 
Carlgren describes a specimen of Sargatia undata, with a complete symmetry of 8, 
in which there were no directives. On the whole I feel inclined to agree with 
M’Murrich (‘‘Contributions to the Morph. of the Actinozoa: IV. On some 
irregularities in the number of the directive mesenteries in the Hexactiniz.” 
Zool. Bul., Boston, I., 1897, p. 115), that this genus should be placed among 
the Bunodide. 
