BIGELOW: COAST WATER EXPLORATION OF 1913. 20d 
may note that great numbers of this species were taken by fishermen 
in Massachusetts Bay in the ensuing November and December. The 
commonest species was S. democratica. It was not taken over the 
edge of the shelf south of Nantucket and Long Island. But it swarmed 
on the surface off Barnegat (Station 10069); and was taken at all the 
stations further south, though it was far less abundant in the Gulf 
Stream than at certain localities near land, e. g., Stations 10069, 
10075, 10079, 10080, 10081, and 10082. But it was not universally 
common over this part of the shelf, there being regions of scarcity. 
off Delaware Bay and off Chesapeake Bay (Stations 10070, 10072, 
10074, 10078). All the captures were from temperatures higher than 
65°. Salinity was about the same (32.1% -32.4%o) at several of the 
poor Stations (10070, 10072) as at several rich ones (10069, 10079, 
10080, 10081); and the total range of salinity occupied by the species 
was very great (32.27%po to 35.25% o). . The unequal quantitative dis- 
tribution of Salpa democratica is, I believe, an index of the abundance 
of the food supply, not of the amount of Gulf Stream water. Dur- 
ing the early summer the surface temperature rises sufficiently to make 
the coast water a favorable habitat for the Salpae which are dispersed 
| over this part of the continental shelf by the constant mixture between 
|land and Gulf Stream water, and wherever they find a plentiful food 
| supply, they reproduce with marvelous rapidity. Examination of the 
/ intestinal contents of S. democratica supports this view, for the speci- 
\mens taken at Stations 10069, 10077, 10081 contain large amounts 
jof diatom and peridinian debris. Salpa democratica occasionally 
swarms in the Gulf of Maine, for example, off Chatham in September, 
/1912 (1914a), though not encountered there in 1913. 
| The five other species of Salpa do not agree in distribution with S. 
democratica, for they were all absent in the coastal belt south of New 
“York, (Stations 10069, 10075, 10078 off Hog Island, 10079, 10080, 
10081 and 10082), 2. ¢., just where democratica was most abundant (p. 
275). Salpa zonaria was second to democratica in the number of sta- 
‘ions at which it was observed, but unlike the latter, it was most 
vbundant at the edge of the Gulf Stream and over the outer part of 
he shelf (Stations 10064, 10071, 10072, 10074); absent close to land. 
| Salpa fusiformis was even more restricted to the edge of the Gulf 
stream, being most abundant in the deep hauls at the Stations where 
vulf Bhan water was purest (10064, 10071), much less so off Chesa- 
wake Bay Station (10076). It was not found anywhere over the 
ontinental shelf, except a few specimens at Station 10070. 
! Our only capture of S. cylindrica was at the most typical Gulf 
tream Station (10071), where it was numerous, far outnumbering 
| 
; 
/ 
