414 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
Finally, a phenomenon of some interest is the apparent ‘absence of 
Meganyctiphanes norvegica from Massachusetts Bay at all seasons. 
There seems to be nothing in temperature or salinity to bar it from 
the waters of the Bay, for in summer, at some depth, the Bay closely 
reproduces the combination of temperature and salinity in which we 
found it swarming in Eastport Bay in August (salinity about 32.4% te 
32.6% , temperature 52°); and in winter the Bay is very little colder 
tham the northern part of the North Sea, where Meganyctiphanes is 
common at that season. Its absence or rarity in the Bay is perhaps 
as Kramp points out, both salinity and temperature would allow its 
existence. His explanation is that it is prevented from spreading 
being, according to his view, chiefly an inhabitant of the deeper water 
layers. But it can hardly be shallow water which bars it from Massa- 
found in swarms on the surface at Eastport, in water of almost pre- 
cisely the same temperature and salinity as the surface water off Cape 
Ann in November. Food supply, not hydrographic conditions, may 
be the factor which determines the local occurrence of Meganycti- — 
phanes in the Gulf. 
PLANKTON FROM GEORGES BANK. 
ton on his first visit, for the samples contained a considerable 
number of copepods, chiefly Calanus finmarchicus and Temora longi — 
cornis in the proportion of about 5-2; Sagitta elegans, and many 
specimens of the small Anthomedusa Hybocodon prolifer, with a | 
young Staurophora mertensit.- The list also includes occasional 
specimens of Oikopleura dioica and Tomopteris hel golandica, besidt 
many Arachnactis larvae; but the most interesting find is a large 
number of small colonies of two species of campanularian hydroids 
which were evidently living under pelagic conditions at the time, 
because the stems present no broken ends, but are growing actively 
