BIGELOW: COAST WATER EXPLORATION OF 1913. 269 
yielded many Euthemisto, the rest of the catch consisted of such 
typical Gulf Stream species as small “black fishes’? (Myctophidae), 
swarms of Salpae of several species (p. 275), Doliolum, Phronima, 
Vibilia, Saphirrina and other species of copepods not taken in the 
cold waters nearer shore (p. 296); and such typical warm water coelen- 
terates as Rhopalonema velatum, Physophora hydrostatica, and Agalma 
elegans (p. 316). But the haul from twenty-five fathoms yielded 
little except hundreds of colonies of Agalma elegans, with only a few 
_Salpae; and the surface water was practically barren. Along this 
part of the coast Gulf Stream fauna was confined to the waters outside 
the continental shelf, for as we ran shoreward once more a typical 
-Calanus plankton in great abundance was encountered, together with 
other boreal organisms, over the forty fathom curve (Station 10065). 
Cape Cod is often spoken of as the dividing line between warm 
and cold water faunae on our coast; ‘but at the time of the cruise it 
was not until we neared New York that any decided change in the 
eharacter of the plankton of the coast water was noted. East of this, 
and in the Gulf of Maine (p. 285), copepods, chiefly Calanus, every- 
‘where played an important role, though occasionally overshadowed 
by the extraordinary abundance of some other organism, for example, 
the hydroids on George’s Bank, and the swarms of Euthemisto south 
of Block Island. But they were a very insignificant part of the 
plankton south of New York and were occasionally entirely lacking 
in the hauls. Near New York (Stations 10067 and 10068) the water 
was filled with swarms of Pleurobrachia pileus to the exclusion of 
| almost everything else, except on the immediate surface, where the 
no. 20 net brought back a considerable number of small copepods 
| (Centropages typrcus). A few miles further south (Station 10069) 
large numbers of Salpae (p. 277) were seen on the surface close to land. 
At this Station, too, swarms of the large warm water ctenophore, 
| Mnemipsis leidyi, which has never been known to enter the Gulf of 
Maine, but which is common along shore as far as Cape Cod later 
in the summer, were noted for the first time. Other interesting 
coelenterates, common near the surface at this Station and further 
-|south, are the well-marked southern variety of the large hydromedusa, 
| Aequorea groenlandica, and the pale southern Cyanea (p. 315). But 
all these warm water forms seem to have been limited to a shallow 
surface zone, because the haul from fifteen fathoms yielded great 
jnumbers of Plewrobrachia pileus, but no Salpae or Mnemiopsis, and 
only a few Aequorea which were probably caught near the surface. 
Besides the Pleurobrachia there were about twenty Aglantha digitale 
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