Pelagic Hyperiidea — Bary 
321 
The species discussed normally inhabit wa- 
ters of a restricted and specified range of 
properties. However, the subantarctic species 
Parathemisto gaudkhaudii and Cyllopus spp, 
and the Coastal species P. australis and P. 
gradlipes occur together at Stations 308, 292, 
330, 310, 279^ and again at Station 189 (Figs. 
1, 2); again, the subtropical species Hyperoche 
mediterranea and the coastal species P. aus- 
tralis and P. gradlipes occur at Station 79- 
These collections of amphipods of mixed 
origin are present along with other species 
belonging to one or more of the several indi- 
cator groups of species. This is interpreted as 
evidence that the waters in which the species 
are habitually present are mixing together. 
The water movements in the area have been 
deduced from the combined evidence of dis- 
tributions of salinities, temperatures, and the 
2 ooplanktonic indicator species. They are dis- 
cussed in detail elsewhere (Bary, 1959), but 
the isotherms of Figures 5 and 6 serve as a 
basis to recapitulate the main features. Briefly, 
there appears to be a moderately strong in- 
fluence from water of subtropical origin 
which extends from the west into Foveaux 
Strait and can be traced around the coast to 
Dunedin and beyond. It is probable that some 
water of subantarctic origin, mixed with the 
subtropical water, also enters the Strait from 
the west. Water of subantarctic origin peri- 
odically penetrates in smaller or larger in- 
trusions into the waters in the Strait and 
coastal areas. These several waters mix to form 
one of intermediate properties which is desig- 
nated herein as "coastal water” (Fig. 1). It is 
believed probable that only water of sub- 
antarctic origin is present at Stations 826 and 
921 of Series 7, and possibly also at Station 
725 (Figs. 1, 6c). Data from stations of Series 
5 and 6 (Fig. 6), together with those from a 
surface thermograph trace made two weeks 
later, on a course parallel to and seaward of 
the stations of Series 6, indicate the location 
of the subtropical convergence. It was not 
crossed by "Lachlan” in January when it was 
probably to the north of Station 1, but it was 
present a little northward of Station 330 in 
March (Series 6). 
With the species of Amphipoda related to 
their respective waters by the T-S-P dia- 
grams, their presence or absence at a station 
becomes significant in that there is an indica- 
tion of the waters present. The subtropical 
species Hyperoche mediterranea is confined to 
that portion of Foveaux Strait likely to be 
most directly influenced by water of sub- 
tropical origin (Fig. 5^). The coastal species 
Parathemisto australis and P. gradlipes occur 
along with H. mediterranea, but in all series 
they occur over a larger area, and a wider 
range of temperatures. From Figure to d, 
it is clear that neither subtropical nor coastal 
species penetrate into areas where the influ- 
ence of water of subantarctic origin is strong, 
e.g., Stations 210 to 218 (Fig. 5c, g), or 285, 
297 (Fig. 5^, h). On the other hand they are 
found, together with subantarctic species, at 
those stations in the mixed waters immediately 
northeast of Stewart Island (Fig. 5^, e) and 
more especially at Stations 187, 189 (Fig. ^jb, 
/), 208 (Fig. 5c, g), 279, 292, 308, 310 (Fig. 
5^, h), and again at Station 330 (Fig. 6d, e). 
In the T-S diagram (Fig. 1) these stations 
(except 187, 189) are seen to extend as a group 
between water of subantarctic origin and 
coastal water. In the T-S-P diagrams Figures 
2, 3 the occurrence of the subantarctic species 
of plankton at all of these stations emphasises 
a certain affinity between them; it would seem 
that they are directly within the influence of 
water of subantarctic origin. This is con- 
firmed by the geographic charts, which sug- 
gest that although some of the stations are 
located in inshore waters each, in fact, is lo- 
cated in the vicinity of tongues of colder 
water penetrating shorewards. This is espe- 
cially so for Stations 279 and 292, less so for 
Station 208. Stations 308 and 310 appear to 
be in waters that are more generally mixed, 
but into which water of subantarctic origin 
appears to be intruding, particularly about 
Station 297 (Fig, 5^, h). Stations 187 and 189 
(Fig. 5^, /) are also located near intruding 
