HYDROID ZOOPHYTES. 31 
GENUS CAMPANULINA. 
The genus Campanulina was instituted by Professor E. van Beneden for a species 
that is known to produce one of the meduse of the genus Phididium. The 
hydrosome stage is characterised by the conical hydrotheca closed by an operculum 
formed of convergent segments of its margin and by the conical hypostome. 
The specimens obtained by the ‘ Discovery’ have all the important characters 
of the hydrosome thus described, and so have the specimens described by Dr. Hartlaub 
(9: pp. 10-11; Pl. I, figs. 8-9) under the name Campanulina belyice, from within 
the Antarctic Circle. 
The absence of the gonophores in both specimens. rendered it impossible for us 
to determine whether they are or are not phanerocodonic. Even if they had proved 
to be adelocodonic, however, they should in our opinion be still retained in the 
genus Campanulina, as the case of Perigonimus antarcticus may serve as a warning 
that the setting free of the meduse is not a character that can be used as 
absolutely diagnostic of a genus when applied to these sub-glacial species. It is 
interesting to note in this connexion that Mr. Hodeson (12: p. 397) states that 
Phialidium meduse were abundant in McMurdo Bay. 
CAMPANULINA A. 
Locality —MecMurdo Bay, February 20th, 1902; 5-20 fathoms. 
A single colony of this delicate little hydroid was found growing over a stem 
of Halecium arboreum and over the Perigonimus antarcticus which encrusts it. 
LHydrosome.—The hydrocauli are slender (0°05 mm. in diameter and 0°5-1 mm. 
in length), more or less clearly marked throughout with spiral lines, and very 
occasionally branched. They arise from a creeping 
The perisare at the distal ends of the hydrocauli gradually dilates to form the 
“ovato-conic” hydrothece, 0°4 mm. in length by 0°1 mm. in diameter. The 
hydrotheca itself is very thin and evidently very flexible. Its margin is deeply cleft 
to form about eight triangular flaps (0°1 mm. in length), which can close together 
filamentous hydrorhiza. 
to form an operculum. It is difficult to determine with any certainty the exact 
number of these flaps, as they are extremely thin and transparent. 
The hydranths, when contracted, completely fill the hydrothecee. The hypostome 
is conical and surrounded by a single circlet of about twenty tentacles, 0°2 mm. 
in length. - 
Gonosoime.—-Unknown. 
CAMPANULINA B. 
Locality.—McMurdo Bay, February 20th, 1902 ; 5-20 fathoms. 
A single small colony of this form was found on Campanularia verticillata 
(var. grandis). 
