HYDROID ZOOPHYTES. 17 
Bonnevie (5: pp. 469-471) in 1898 instituted the genera Lampra and Gymnogonos, 
This authoress includes all the species belonging to this group of genera with 
“medusoid” gonophores in the genus Corymorpha. All species with ‘“ pseudo- 
medusoid” gonophores are placed in the genus Lampra, and those with “styloid ” 
gonophores in the genus Gymnogonos. 
This classification appears to us to be reasonable and will probably serve a useful 
purpose for some years. Ditticulties are sure to arise later when species are found with 
intermediate characters, but at present we can recognise three distinct steps in the 
degeneration of the medusiform gonophore which may he used for purposes of 
classification. There is the “medusoid” gonophore showing some evidence of 
degeneration, but retaining the endocodon or sub-umbrella cavity, the ‘“ pseudo- 
medusoid ” gonophore retaining the umbrella wall, but with no sub-umbrella cavity ; 
and, lastly, the “styloid” gonophore with little or no definite trace of medusoid 
structure. 
LAMPRA PARVULA. 
(Plate IIIL., figs. 15, 16; and Plate IV., fis, 35.) 
Localities. —Off Hut Point and Flagon Point in McMurdo Bay. Sexually mature 
and full-grown specimens obtained from September to December, 1902, and September, 
1903. Young specimens obtained January, February, March and October, 1902, and 
January, 1903. Depth, 10-20 fms. 
A great many specimens of this interesting little species were found in several 
tubes and bottles from the localities named above. They are attached by root-like 
processes from the basal end to polyzoa (fig. 15) and to a curious felt-work mass of 
substance that is mainly composed of sponge spicules (fig. 16). Although Lampra 
parvula presents us with the largest hydroid zooid, except those of LZ. microrhiza and 
of Tubularia in the collection, yet they are considerably smaller than the zooids of any 
known species of Lampra or Corymorpha. The zooids of the only known species of 
Gymnogonos, however, are only 10-20 mm. in height. Like many other species of 
Corymorphidae, the colour of the spirit specimens is dark reddish-brown. 
In habit the species closely resembles Lampra socia (Swenander, 238: pp. 6-8, 
figs. 1-2) from the Trondhjem fjord, several specimens being usually found in groups 
more or less imbedded in the sponge débris mass. A few very young specimens were 
found attached singly to the stems of calcareous polyzoa (fig. 15), or more rarely to 
other hydroids. L. socia was found attached to the branches of Lophohelia prolifera. 
Hydrosome.— The height of the full-grown polyps from the base to the mouth is 
about 30 mm. 
In a great many specimens (fig. 16) there is a sudden diminution in the diameter 
of the polyp about half the distance from the base to the tentacles. The position of 
the constriction varies a good deal in different specimens, and in some it is hardly 
noticeable, the stems gradually tapering from the base to the neck. The thicker basal 
VOL, Ill. ZE 
