bo 
bo 
SYDNEY J. HICKSON anp F. H. GRAVELY. 
FAMILY PLUMULARIIDAE. 
PLUMULARIA GLACIALIS. 
(Plate III, figs. 23, 24.) 
Locality.—* Kast end of Barrier,” January 29th, 1902; 100 fms. 
From the nature of the hydrorhiza, which was curved, it seems probable that 
the specimens of this species were attached to a weed or zoophyte. 
Llydrosome.—A_ stout fascicled hydrocaulus (fig. 23) 300 mm. in height and 
2*5 mm. in diameter near the base arises from the densely matted but imperfectly 
preserved hydrorhiza. 
In the constitution of the hydrocaulus there is a single tube (fig. 23, 4. hel.) 
giving off, alternately right and left, hydrocladia which may be 30 mm. in length 
and are usually divided into two equal branches. Supporting this single tube that 
bears hydrocladia are several other tubes (¢. sp.) which bear nematophores only. The 
supporting tubes do not surround the hydrocladia-bearing tube, but leave it exposed 
on one side. The hydrocladia-bearmg tube is divided into a series of internodes 
1 mm. in length, and it becomes free from its supporting tubes at the distal end, so 
that the hydrocaulus then becomes monosiphonic. In Plumularia profunda (Nutting, 
18: pp. 66-67; Pl. VIIL, figs. 2-3), to which our species has some affinities, the 
supporting tubes entirely surround the hydrocladia-bearing tubes, and the internodes 
are of two kinds, longer ones supporting two hydrocladia and shorter ones bearing’ 
only one hydrocladium. Moreover, in Plumularia profunda the hydrocladia are 
supported on processes arising from the proximal end and not from the middle of 
the internodes as they are in our species. 
A short hydrotheca (0*2-0°3 mm. in height), adnate to the hydrocaulus but 
not adnate to the hydrocladium, is found at the base of each hydrocladium (fig. 23). 
The other hydrothecee are cup-shaped, 0°3 mm. in length and 0*2 mm. in diameter 
at the mouth. One, or sometimes two, arise from each internode of the hydrocladia, 
and each one is guarded by two nematophores above (ic. distally) and a single one 
below. The margins of the hydrothece are entire. 
Although the label of the bottle contaiming these specimens bears the inscription 
has been dry,” some of the hydranths are sufticiently well preserved to enable us 
to make out some features of the structure of the soft parts. The rounded hypostome 
is surrounded by a single circlet of about fifteen tentacles, each about 0°15 mm. 
ce 
in length. 
Gonosome.—The female gonothecee are 1°0 x 0°5 mm. in size, and have a 
remarkable shape (fig. 23, @ gth.). The aperture is found on the distal flattened 
end of the pear-shaped structure, but instead of being at right angles to the stem, 
is turned inwards through an angle of 45° so as to face inwards and upwards. This 
