802 SUBANTARCTIC ISLANDS OF NEW ZEALAND. [Summary of Results. 



considered by Budde-Lund as forming a subfamily, and it is found only in the sub- 

 antarctic regions and the southern extremities of the great continents. A still more 

 striking example is afforded by the Serolidae, a marine family of Isopods. Not- 

 withstanding their marine habitat, and the fact that some of them extend into deep 

 water, they are almost entirely confined to subantarctic regions, being represented 

 at New Zealand, Patagonia, Chili, South Shetlands, South Georgia, Marion and 

 Prince Edward Islands, Crozets, Kerguelen, and Australia, while one species, which 

 is perhaps doubtful, is recorded from California, 



Another group of the Crustacea that is widely distributed in subantarctic regions 

 is that section of the fresh-water Copepoda that includes the genus Boeckella and 

 allied genera. Boeckella was first established for a New Zealand species, B. triarti- 

 culata (G. M. Thomson), and Sars has described two other New Zealand species of 

 this genus, although it is doubtful if they are more than varieties of the first. Dr. 

 Al. Mrazek, in his account of the fresh-water Copepoda collected by the Hamburg 

 Magellan Expedition, points out that this group consists of comparatively large 

 forms readily secured with the surface-net in open sheets of fresh water, and they 

 are therefore likely to be more easily captured than the smaller Copepoda living 

 among weeds on the edges of small ponds, and that consequently, although our 

 knowledge of the group is not perfect, a fair idea of its distribution is already obtain- 

 able. In South America, the Falklands, and South Georgia the group is represented 

 by several species for which Mrazek establishes new genera closely allied to the 

 original Boeckella ; one species of these, Parahoeckella hrevi-caudata, is also found in 

 Kerguelen. A species belonging to the same group, Deguernea antarctica, has been 

 described by Thomson from Macquarie Island ; Mrazek considers this a young form 

 of a species of uncertain position, but undoubtedly a Boeckellid. The genus Boeckella 

 is also found in the alpine lakes and tarns of Tasmania, where it apparently dis- 

 places the northern genus Diaftomus, and Geoffrey Smith (1909a, p. 137) has recently 

 called attention to the importance of the distribution of the genus. The group 

 is, therefore, widely distributed in all subantarctic lands, but it nowhere extends 

 into the tropics, and may be looked upon as a group that has arisen, perhaps, 

 in the Antarctic Continent. This appears to be confirmed by this discovery of 

 a species in fresh- water pools on the Antarctic Continent itself — -viz., at Hoffnungs- 

 bucht, in Louis Phillipe Land, during the Swedish Antarctic Expedition. Dr. Gunnar 

 Andersson was forced to winter there with two companions, and in a small pool filled 

 with fresh water from the melting ice, near the winter station, he found specimens 

 which he collected with difficulty and preserved with care throughout the long and 

 dreary winter spent at that place. I have not yet seen the full account of this 

 species, but in Andersson's account of this part of the expedition (Nordenskjold, 

 1904, p. 164) it is stated that it was examined by Dr. Sven Ekman, and found to 

 be a species of Boeckella closely allied to the Patagonian species B. entzii; it will 

 perhaps be assignable to one of the genera established by Mrazek. 



In the Mollusca certain marine genera that are distinctly confined to subant- 

 arctic regions have been already mentioned; and the Phenacohelicidae, a family 

 of land-snails, has a similar distribution. To this it may be added that the 

 fresh-water mussels of the genus Diplodon are found over the whole of South 

 America, in New Zealand, the northern rivers of Tasmania, Australia, and New 

 Guinea. 



