30 EDWARD T. BROWNE. 
The ‘Southern Cross’ collection contains three specimens, taken at Cape Adare. 
The largest is in a mutilated condition, having a clean-cut hole through the centre 
of the umbrella. The stomach and mouth have completely disappeared, and so also 
have the proximal ends of the gonads, but the margin of the umbrella is in good 
condition. The two other specimens are intermediate stages in bad condition. 
The ‘ Discovery’ collection also contains a mutilated specimen, which was taken 
in McMurdo Sound on 27th March, 1903, through one of the holes in the ice. 
Description of the Adult—Umbrella slightly convex, and thick, about four times 
as broad as high. Velum broad. Four radial canals with sinuous margins in the 
gonadal regions, but without conspicuous lateral diverticula. Gonads large and broad, 
arranged in lateral and transverse folds, and extending over nearly the whole length 
of the radial canals. Tentacles long and slender, about 300, with a reddish pigment 
in the endoderm, and with laterally compressed basal bulbs. One long club-shaped 
cordylus between every two tentacles. 
Size.—Umbrella up to 60 mm. in diameter. 
Notes on the Specimens.—The ‘ Discovery’ specimen shows that the gonads extend 
from the base of the stomach nearly to the circular canal. They are arranged in a 
series of lateral folds, along both sides of the radial canals, and form a closed fube. 
There is no evidence of a mouth extending over and along the gonads, a character 
which distinguishes Staurophora from Ptychogena. The radial canals of Ptychogena 
antarctica have not the conspicuous lateral diverticula of P. /actea. In the proximal 
part of the canals there about two very short irregular diverticula, but the margins of 
the canals are of a rather irregular wavy nature, so that the pinnate arrangement of 
the gonads, conspicuous in P. lactea, is absent in this species. 
The tentacles are closely packed together round the margin of the umbrella, and 
are like long, slender threads, some of which measure 40-50 mm. in length. The 
endoderm of the tentacle, including the basal bulb, contains a dark reddish pigment 
(in formalin). Sections show that the pigment is in minute globules, either isolated 
or grouped in clusters. The ectoderm of the tentacle is thick, and composed of many 
layers of very small cells, amongst which are numerous long slender nematocysts, 
about 15 » in length. The nematocysts frequently congregate in clusters or layers 
adjacent to the mesoglea, and look in that position just like spicules. The basal bulbs 
of the tentacles are laterally compressed (PI. IL., fig. 8) and the upper (aboral) side of 
the bulb is arched, but when viewed from the aboral side, the basal bulbs look long 
and tapering (Pl. IL, fig. 7). 
The cordyli are long and club-shaped (fig. 9), and are situated on the-margin of 
the umbrella close to the velum. There is usually only one cordylus between every 
two tentacles. The cordyli are without pigment. Some of the cordyli possess just a 
few nematocysts similar to those in the tentacles. I have not noticed nematocysts in 
a cordylus before, but here at any rate is an exception to the rule. Haeckel (1882) in 
his description of Ptychogena pinnulata states that the cordyli appear chalk-white in 
