PLANKTON OF THE GULF OF MAINE 307 
Oncsea conifera. — Twelve specimens, including both sexes, were taken at the 
surface in the Eastern Channel, April 16, 1920, station 20107. 
Oncsea minuta. — Fifteen males and females were captured in a vertical haul in 
deep water southeast of Georges Bank, March 12, 1920, station 20069. 
Oncsea venusta. — Twenty-five males and females were found in a vertical haul 
south of Georges Bank, February 22, 1920, station 20044. 
Scolecithricella obtusifrons. — Three females were captured in a vertical net in 
deep water southeast of Nova Scotia, March 19, 1920, station 20077. 
Scolecithricella ovata. — Twenty females were taken in a vertical net south of 
Georges Bank, February 22, 1920, station 20044. 
Temora stylifera. — A single female was captured in a vertical net southeast of 
Nova Scotia, September 6, 1915, station 10313. 
Tisbe furcata. — A single female was taken at the surface just outside Boston 
Harbor, April 6, 1920, station 20089. 
Daphnids (Cladocera) 
These little crustaceans are often extremely plentiful in the coastwise waters 
\of boreal seas, especially of the North Sea region. It is probable that they are an 
important element in the plankton of estuarine situations all around the coast line 
of the Gulf of Maine, for McMurrich found the genera Podon and Evadne regularly 
at St. Andrews during the summer months, often in abundance, while to the south 
of our area Fish (1925) reports both Evadne and Podon in abundance at Woods Hole 
and in Long Island Sound. The group as a whole, however, is so strictly neritic 
that it hardly figures in the planktonic communities of the open gulf more than a 
few miles out from land, except at rare intervals for brief periods, and is only acci- 
dental outside the 100-meter contour. 
Only one cladoceran genus — Evadne — has yet been noted in our catches, and 
because of its slight importance in the natural economy of the offshore waters of 
the Gulf of Maine no attempt was made to list the occurrence in the towings of 
1912 to 1914. A preliminary survey of the surface towings for 1915 located it at 
stations 10287, 10302, 10303, 10313, 10317, 10318, and 10319 and in Shelburne Har- 
bor, Nova Scotia. In 1916 Evadne was recorded at only one Gulf of Maine station- 
10398. All these localities, as I have already stated (p. 35), lie within 15 miles 
of land. It did not appear in the samples of the catch at the other summer sta- 
tions, which were passed under the microscope, but as examination of larger amounts 
of the plankton might have disclosed occasional specimens of Evadne, the most that 
can be said is that it was certainly scarce if not actually absent at the stations where 
it was not recorded (also on Georges Bank, August 13, 1926). 
Evadne was not found at all in the spring towings of 1920 or during the winter 
and early spring of 1920-1921, but in August, 1922, it appeared at several stations 
in Massachusetts Bay (10636, 10637, 10638, 10640, 10641, 10643, and 10644). Up 
to that time we had found it in large numbers on only two occasions, namely, 
near Cape Elizabeth, September 20, 1915 (station 10319), and Cape Cod Bay, August 
24, 1922 (station 10644), most of the other records being based on only a scattering. 
On August 18, 1924, however, after this report was ready for the press, surface tows 
