PLANKTON OP THE GULP OP MAINE 289 
and over the deep trough within the Gulf of St. Lawrence (Willey, 1919), and its 
range extends far out into the ocean off Labrador, as just noted (p. 287). 
Seasonal distribution . — McMurrich (1917) has remarked that Temora occurred 
at intervals at St. Andrews during the autumn of 1914 and up until January 27, 
1915 (on which date it was the dominant component of the plankton), but not at 
all from February to mid-May. His unpublished plankton lists for November, 1915, 
to October, 1916, carry the observations a step farther, showing Temora constantly 
present at St. Andrews, and in considerable numbers, from mid-September through 
January, but only at intervals, and represented by odd individuals, during the other 
months. Wheeler (1901) and Fish (1925) have likewise found it much more plentiful 
at Woods Hole in winter than in summer. 55 
Temora longicornis has been recorded in the open waters of the Gulf of Maine 
in every month in the year except November and February, when few tows have 
been studied for their copepods. In the coastwise belt the frequency of occurrence 
has been highest during the period September to January, and again from March to 
April, as indicated by the percentage of stations at which it occurred (about 50 per 
cent in each case), and lowest during the June-August quarter, when it was recorded 
at only 22 per cent of the stations in this region. However, this may reflect an 
annual and not a seasonal fluctuation, because Temora occurred in a much larger 
percentage of our hauls in July and August of 1913 (about 50 per cent in the gulf, 
on Georges Bank, and off Nantucket) than in those months in 1912. It was again 
scarce in the summer of 1914 (14 per cent of the stations on Georges Bank and in 
the gulf; not at any of the stations off Marthas Vineyard); but the year 1915, when 
Temora occurred at about 42 per cent of the stations right through the season from 
May to October, apparently saw the local stock increase once more. The percentage 
of occurrence has been about the same (33 to 38 per cent of the stations) for July- 
August as for February-May on the offshore banks and over the shelf off Nantucket 
and Marthas Vineyard. 
In short, such analysis as I have been able to make does not prove a definite 
periodicity in the frequency of this species in the open gulf beyond suggesting the 
possibility that there is a minimum in midsummer. 
The evidence of the vertical hauls (tables, pp. 297 and 299) is that Temora is 
seldom if ever dominant anywhere in the open gulf at any time, for at the maximum 
it has constituted only 20 per cent of the catch of copepods (station 20062) ; 56 and 
in only six of the many vertical hauls anywhere between the longitudes of Marthas 
Vineyard and Cape Sable has it constituted as much as 10 per cent of the copepods, 
the average for all being only about 3 to 4 per cent of Temora, even if the calculation 
be limited to those stations where this copepod was plentiful enough to be picked up 
by the vertical net. If the stations where it was missed be included, its average 
percentage drops below 2 per cent. The absolute numbers of individuals per square 
meter have been correspondingly insignificant, compared to those of Calanus jin- 
marchicus, at the maximum being only about 18,000 within the gulf, 18,760 off Shel- 
burne, Nova Scotia (station 10313, September 6, 1915), and about 33,000 near Marthas 
88 Williams (1907) reported it as abundant throughout the year in Narragansett Bay. 
86 28 per cent off Shelburne, Nova Scotia, Sept. 6, 1915, Station 10313. 
