PLANKTON OF THE GULF OF MAINE 
267 
Gloucester Harbor (Esterly, in Bigelow, 1914, p. 116). Farran (1910) has classed 
it as a tropical and temperate form, which is corroborated by Willey’s (1919) failure 
to find it in the collections of the Canadian fisheries expedition off Nova Scotia 
and Newfoundland or in the Gulf of St. Lawrence, where it has never been reported, 
and by its absence from the plankton collections made by Herdman off the Straits of 
Belle Isle (Herdman, Thompson, and Scott, 1898); but it ranges eastward along 
Nova Scotia for some distance past Cape Sable, for the Grampus took it at three 
stations across the continental shelf off Shelburne, Nova Scotia, on June 23, 1915 
(stations 10291, 10293, and 10294), and the Albatross found it again near Roseway 
Bank (station 20074) and outside the continental edge on this line (station 20077) 
on March 19, 1920. 
Paracalanus parvus may have been overlooked in the earlier towings in the 
Gulf of Maine because it is so tiny (it is the smallest of calanoids), but the collec- 
tions of 1915, 1920, and 1921 prove it present in the gulf in every month in the 
year except July and November, when no hauls were made— that is, a year-round 
resident. In spite of its brief history in our towings its records extend widespread 
over the gulf, indifferently outside the continental edge, over the offshore banks, 
in both sides of the deep basin, and all around the coastal belt (fig. 80). There are 
also records over the continental shelf off Marthas Vineyard (stations 10331 to 
10333; table, p. 298). 
In spite of the seasonal fluctuations outlined below, the regional distribution is 
as general in the cold half of the year as in the warm half, and Paracalanus occurs 
in all parts of the gulf and about as regularly in one region as another. The plotted 
records might suggest a concentration in the inner parts of the gulf, but in reality 
this merely reflects the greater number of hauls which have been made there, and 
more especially the fact that no towing was done in the southern or eastern parts 
of the basin or on Georges Bank during the summer of 1915. In short, this copepod 
is to be expected anywhere in the region at any time of year. I have not been 
able to subdivide the gulf into regions "rich” or "poor” for this species, whether 
for the year as a whole or for the individual months, the stations where 
catches were larger than the monthly average being widely distributed (fig. 81) 
(having reference to the regional distribution of the hauls in different years and 
seasons) both for the winter-spring and for summer-autumn; but we have taken 
it in much larger numbers off Marthas Vineyard (station 10332 and 10333) than 
anywhere east or north of Nantucket, suggesting that the waters over the conti- 
nental shelf south of southern New England are a center of abundance for it. 
Seasonal fluctuations. — P. parvus has been taken at the following percentages of 
the stations for 1915, 1920, and 1921 (tables, p. 297): 
Date 
Percent- 
age of 
stations 
Date 
Percent- 
age of 
stations 
March, 1920 and 1921 
29 
September, 1915 
75 
April, 1920 
23 
October, 1915 
93 
May, 1915 and 1920 
80 
December, 1920_ 
50 
June, 1915 
100 
January, 1921 .. 
40 
August, 1915 
100 
