PLANKTON OF THE GULF OF MAINE 
379 
The obvious inference from this is that there is a winter maximum and spring 
minimum for Stephanomia in the Gulf of Maine. Other years might yield quite 
different results, however, and it is questionable whether the concentration of 
Stephanomia in the southwestern part of the gulf, suggested by the chart (fig. 103), 
and its apparent rarity in the southeastern part and on Georges Bank, are any- 
thing more than accidental, especially when we remember that the neighborhood 
of Grand Manan is the only locality in the gulf where it has ever been found of 
large size (Fewkes, 1888). 
Alexander Agassiz’s (1865) discovery of very young stages of this species in 
Massachusetts Bay in early summer is undeniable evidence that it breeds in the 
gulf, but how regularly it does so from year to year, what proportion of the local 
stock results from local reproduction and what from immigration, and what rela- 
tionship the fluctuations in the local stock of Stephanomia bear to hydrographic 
conditions are questions for the future. 
Dipliyes arctlca Cliun 
The faunal status of this species is discussed in an earlier chapter (p. 64). The 
Gulf of Maine records are as follows: Southeast slope of Georges Bank, July 22, 
1914 (station 10220) ; outside the continental edge off Shelburne, Nova Scotia, 
June 24, 1915 (station 10295), and March 19, 1920 (station 20077); near Lurcher 
Shoal and in the Eastern Channel, April 12 and 16, 1920 (stations 20101 and 20107). 
Other siphonophores 
The occurrence of Physophora and Physalia is discussed above (p. 55). To 
complete the record of the group in the Gulf of Maine I have only to mention a 
single Dipliyes truncata 19 from the northeast slope of Georges Bank, July 22, 1914 
(station 10220), a few more examples of this species from our deep stations off its 
southwest face in February and May, 1920 (stations 20044 and 20129), and two 
taken in the northeastern basin of the gulf off Grand Manan on April 12 of that 
same year (station 20101). The beautiful Agalma elegans, so common in the inner 
edge of the Gulf Stream and which sometimes even reaches the coast west of Cape 
Cod (Fewkes, 1881), has never been taken within the Gulf of Maine. 20 
Pelagic hydroids 
In an earlier chapter (p. 33) the floating hydroids that we have encountered 
over Georges Bank are mentioned. The records on which this observation is based 
are as follows: 
On April 14, 26, and 27, 1913, campanularian hydroids were found floating on the 
top of the water over the bank (Bigelow, 1914a, p. 414; lat. 41° 37' N., long. 67° 
18' W., and about lat. 41° 40' long. 68° 30'), some of the specimens being complete — 
that is, with all the ends of the stems rounded, closed, and apparently growing, as 
Dr. S. F. Clarke reported on examining them. On the 9th of the following July 
le For a discussion of this species see Bigelow, 1913, p. 73; 1918, p. 422; and Moser, 1913, p. 232. 
!0 Agalmid fragments taken during the summer cruise of the Grampus in 1912 were provisionally referred to this species, but 
subsequent study leads me to believe that they were in reality the common Stephanomia cara (p. 378). 
