8 SYDNEY J. HICKSON ann F. H. GRAVELY. 
Although Eudendrium insigne appears to he widely distributed in the seas of the 
Northern hemisphere, it is not included in Hartlaub’s list (10: pp. 505-509) of 
Southern species. 
SUB-FAMILY BIMERIINAE. 
FENUS STYLACTIS. 
The generic name Stylactis was introduced by Allman for two species referred 
to the genus Podocoryne by Sars (P. fucicolu, and a variety of P. carnea). The 
principal characters that distinguish the genus from Podocoryne are—(1) The 
absence of any superficial coenosare covering the hydrorhizal plexus; and (2) the 
gonophores in the form of sporosacs instead of free swimming medusa. From 
Hydractinia the genus is distinguished by the first of these characters, but it agrees 
with it in the second character. 
Allman placed the genus in his family Bimeriidae, and thus removed it from the 
neighbourhood of the other two genera. 
The opinion of later writers appears to favour the view that Stylactis is more 
closely related to /Hydractinia and Podocoryne than Allman’s classification suggests. 
Bonnevie (5: p. 485) unites Hydractinia and Podocoryne imto one genus, 
Hydractinia, and Motz-Kossowska (17: pp. 81-85) imeludes in the same genus the 
two species that formed the genus Stylactis of Allman, and has added a new species 
HT. pruvoti from the Balearic Islands, which is intermediate in characters between the 
species attributed by older authors to the genera Stylactis and Podocoryne 
respectively. 
We are quite convinced of the general affinities of the three genera, which 
are indeed emphasised by this collection from the Antarctic Sea in so far as we 
have a species of Stylactis with dactylozooids of a simple kind, and a species of 
Hydractinia without dactylozooids, the usual condition beg that Stylactis has 
dactylozooids and //ydractinia has not. At the same time, the hydrorhiza of our 
two forms is so distinct and the minute characters of the gonophores so different 
that we have thought it better to retain the generic name Stylactis and keep it in 
the family Bougainvilliidae for the present. 
STYLACTIS HALECTII. 
(Plate I., figs. 5, 6 ; and Plate IV., fig. 33). 
Locality :—McMurdo Bay; February 28th, 1902. Found at depths of less 
than 20 fathoms. 
A considerable quantity of this interesting species was found encrusting the 
thicker stems of Haleciwm arboreum. It arrived in a fairly good state of preservation 
notwithstanding that the bottle containing it was broken in transit. 
Hydrosome.—The hydranths arise directly from an encrusting hydrorhiza 
