16 EDWARD T. BROWNE. 
tentacles on the one half of the umbrellar margin, and on the other half only twelve 
small bulbs. Another specimen has one short tentacle and five bulbs close together 
in one quadrant, and the other three quadrants are without tentacles, bulbs, or a 
circular canal. These specimens are either congenitally abnormal, or else in the process 
of repairing serious injuries. The latter specimen has every appearance of having lost 
the greater portion of its original umbrellar margin, and the wound seems to have 
healed up. The former probably lost one half of its tentacles and has begun to 
develop a fresh set. 
There is an interesting abnormality in one specimen. From one of the radial 
canals, not far from the top of the umbrellar cavity, hangs down an extra stomach with 
a mouth. The stomach has the shape of a slender tube, and bears a few genital folds. 
The mouth is fairly large for the size of the stomach, and its margin is folded. 
A large Amphipod belonging to the genus Hyperia was found inside the umbrellar 
cavity of two specimens. 
PERIGONIMUS. sp. ? 
In the ‘Discovery’ collection there are four specimens of a little Medusa which 
looks like a very early stage of a Perigonimus. They are all about the same age and 
have not been long liberated from their hydroid. The shape and structure of the 
tentacles are not in favour of this Medusa being a very early stage of Catablema. 
Description.—The umbrella is about 1 mm. or less in length and width, with a 
small conical process on the summit. The stomach is short, and the mouth has four 
little lips. Four radial canals. The gonads have not begun to develop. There are 
two long, opposite perradial tentacles, with large tapering basal bulbs. Two very 
small, opposite perradial and four very small interradial tentacles. 
Famity BYTHOTIARIDZ (Maas, 1905), Bigelow, 1909. 
Genus Srpocira, Maas, 1905. 
sens. em. 
Generic character.—Bythotiaride with four perradial canals; with four or more 
centripetal canals, which may either remain blind canals, or join the radial canals (when 
the latter have the appearance of being branched), or join the base of the stomach. 
Mr. Bigelow (1909) has recently emended Maas’ original definition of the genus, 
so as to be able to include within the genus a new species called Stbogita simulans, 
found in the Tropical Pacific between Panama and Chatham Island, and also in the 
Behring Sea; and another new species called S. nauarchus, found in the Gulf Stream 
off the North American coast. I now find it necessary to slightly alter Bigelow’s 
definition of the genus for the admittance of a new Antarctic species, named Sibogita 
borchgrevinki, in honour of the leader of the ‘ Southern Cross’ Expedition to the South 
Pole. I think it is advisable to leave the structure of the gonads out of the generic 
