BIGELOW: COAST WATER EXPLORATION OF 1913. 283 



Thus the two species were about equally abundant over Nantucket 

 Shoals (Station 10060), in the centre of the Gulf of Maine (Stations 

 10090 and 10091), and in the upper layers near the edge of the Gulf 

 Stream south of Long Island (Station 10064). But comprcssa pre- 

 ponderated ofP Barnegat (Station 10069) and at all the stations near 

 shore in the Gulf of Maine where both were taken, (Stations 10089, 

 10095, 10096, 10097, 10102), as well as on the surface over the eastern 

 basin (10092) ; E. bispinosa over the outer part of the continental 

 shelf south of Nantucket and Long Island, in the deep haul off Chesa- 

 peake Bay, and in the deep hauls in the eastern basin of the Gulf of 

 Maine. When bispinosa outnumbered comprcssa, its preponderance 

 was usually greatest in the deep hauls. 



Both species were living at a wide range of temperature, with a 

 maximum of about 69° (Station 10066, surface). iVnd swarms of 

 bispinosa were taken in water as warm as 67° (Station 10062, surface) ; 

 but comprcssa was not common in water warmer than 62° (Station 

 10092), and most of its captures must have been from consid- 

 erably colder water. The lovfest temperatures for both was about 

 42° (deep hauls in the Gulf of Maine); and bispinosa must have 

 been living in numbers in this cold water, because plentifully repre- 

 sented in one of the deepest hauls in the Gulf as well as in the shal- 

 lower ones (p. 282) . 



The range of salinity was likewise very wide for both species, 

 with an upper limit of 35.2%o (the deep haul at Station 10064) and 

 a lower limit of about 31.5%o (surface. Station 10066). But it was 

 only once that either was taken in water fresher than 32%o, and the 

 freshest water in which they were abundant was 32.8%o for bispinosa 

 (surface, Station 10062), 32.6%o for comprcssa (surface. Station 

 10092). 



The data outlined above suggest that both comprcssa and bispinosa 

 belong to the coastal, not oceanic waters, of which comprcssa, at least, 

 is almost as regular an inhabitant as Limacina bcdea, Calanus, or in- 

 deed any of the typical boreal plankton animals. Both species, it is 

 true, were found in large numbers, and of unusually large size, in the 

 deep water under the edge of the Gulf Stream ; but the fact that this 

 was only where the surface of the stream was considerably diluted 

 with fresh water, and that both were absent in the Gulf Stream water 

 proper (Station 10071, 10073) shows that neither of them is a regu- 

 lar inhal)itant of the stream. They thrive below the inner edge of 

 the stream, not because of temperature or salinity, but because of the 

 abundant food supply. 



