458 Happon—The Actiniaria of Torres Straits. 
STELIDIACTIS, Danl. 
Sagartids with a soft body-wall and a clasping base that secretes a cuticle; 
the cinclides occur irregularly about the middle of the column, at the bottom of 
twenty-four longitudinal grooves; oral disk of about the same diameter as the 
column ; tentacles 24 or 48 short, conical completely retractile; six pairs of 
sterile perfect mesenteries, the other large mesenteries are fertile. 
This definition is compiled from Danielssen’s account of his two species, 
S. Mopsie and S. Tubularie. It is not satisfactory to criticise forms of which one 
has no acquaintance, but I suspect that these two are merely varieties of the same 
species, which externally resembles Gephyra Dohrnii, von Koch. I have previously 
(Trans. R.D.S. (2), 1v., 1889, p. 825) recorded the latter species from the south- 
west of Ireland. 
Sub-Family.—Cuonpractinun&, Hadd. 
Sagartiide with only six pairs of perfect mesenteries, which alone of the 
well-developed mesenteries are sterile; two gonidial grooves and two pairs of 
directives, body-wall usually thick, with a cuticle and often nodulated ; cinclides 
absent(?); acontia rarely emitted, and then by the mouth only; strong mesogleal 
sphincter muscle. 
In this sub-family I originally (1889, p. 305) included the genera Chon- 
dractinia, Hormathia, Chitonactis, Actinauge, and Paraphellia. Simon, Carlgren, 
and Kwietniewski believed that Phellia belongs to this group, and so have 
restored the older term Phelliinie. As Phellia has its primary cycle of 
mesenteries alone fertile, we must remove it from the other forms, and so my 
name stands. 
SYNOPSIS OF THE GENERA. 
Capitulum. Scapus. Tentacles. 
Actinauge, ... ridged. tuberculate. basal swellings. 
Hormathia, .... smooth. 5 no basal swellings. 
Chitonanthus, ... ridged. a » » 
Paraphellia, .... smooth. smooth. 5 99 
?Stephanactis, ... i a sy i clasping base. 
Phelliactis, ... 3% Pa basal swellings. 
?Ammonactis, ... a . Be elongated. 
