BIGELOW: EXPLORATIONS IN THE GULF OF MAINE. 107 
Norway, the English Channel, the northeast coast of Scotland, and 
from the Grand Banks of Newfoundland; and Sagitta elegans is a 
characteristic member of the North Sea plankton. 
Most oceanic species so far detected in the collections, e. g., Salpa 
mucronata, and S. fusiformis, Sagitta serratodentata, Agalma elegans, 
Physophora hydrostatica, are dwellers in warm or in temperate waters, 
the only far northern records of any of them being obviously the 
result of warm currents (for northern records of Salpa, see Apstein, 
1909: of Sagitta serratodentata, see Ritter Zahony, 1911; Agalma and 
Physophora, see Bigelow, 1911. And the resemblance which the Gulf 
bears in a small way, to the Norwegian Sea in the more important 
constituents of its zodplankton, is heightened by the fact that Salpa, 
Agalma, and Physophora are regular summer visitors to the latter 
with the northward movement of Atlantic water (Helland Hansen 
and Nansen, 1909, Murray and Hjort, 1912), while their presence in 
our Gulf is positive evidence of an influx of water from the northern 
edge of the Gulf Stream. 
List OF FISHES. 
(Identified by W. W. Welsh, U. S. Bureau of Fishertes). 
1. Larval and postlarval stages taken in the plankton hauls. 
ARGENTINIDAE. 
Smelt. Osmerus mordax (Mitchill). 
~ Portland Harbor July 31 Surface 1 specimen 19.5 mm. 
Herring Smelt. Argentina silus Ascanius. 
Station 27 August 14 35 fathoms 1 specimen 49 mm. 
GASTEROSTEIDAE. 
Three-spined Stickleback. Gasterosteus aculeatus Linné. 
Station 11 30-0 fathoms 1 specimen 2.3 cm. 
Station 23 surface 4 specimens 3.9-3 cm. 
Station 25 _—_ surface 8 specimens 3.9-2.8 em. 
August 13 surface 4 specimens 4.4-3.7 cm. 
Station 29 —_ surface 1 specimen 4.6 cm. 
Station 30 surface 11 specimens 4,.2-2.8 cm. 
August 16 surface 1 specimen 4.2 cm. 
Station 43 surface 2 specimens 3.3-2.8 em. 
