158 
BULLETIN OF THE BUREAU OF FISHERIES 
by a large tropical element (e. g., station 10218, July 21, 1914). Thus its abundance 
along the outer edge of the shelf does not imply an oceanic origin, but, like Calanus, 
it is typical of the water of the coastal banks off the Gulf of Maine and along the 
American litoral as a whole, finding the inner edge of the so-called Gulf Stream a 
fluctuating barrier to its seaward dispersal, which is in line with its boreal nature. 
Euthemisto is not only more numerous over the outer part of the shelf than 
within the Gulf of Maine, but it grows larger there, although very large specimens 
occasionally occur even close to land. VvTten adult females with eggs are taken in 
our coastwise hauls they are seldom over 10 millimeters long, with the general run 
of the catch still smaller, whereas the numerous adults taken over the offshore banks 
are often as long as 20 millimeters. 
Although we know little of the status of Euthemisto in the offshore parts of 
the gulf in autumn, there can be little doubt that an inshore movement of greater 
or less extent takes place at that time, for in 1915 this genus occurred in some numbers 
in October in Massachusetts Bay, where it is usually scarce or absent in summer 
(p. 156). Apparently it reaches its maximum abundance in the coastal zone of the 
gulf in October and November, and during the third week of November in 1912 it 
was comparatively common near Gloucester (Bigelow, 1914a, p. 403). To judge 
from the season of 1920 and 1921, however, this autumnal increase is followed by 
shrinkage in its numbers with the onset of winter, for in late December and early 
January we took Euthemisto at only 5 out of 14 stations in the northern and western 
parts of the gulf — never more than a few specimens in any haul — nor did it appear 
in any abundance later than November during the winter of 1912-1913, though a 
few were noted at all our stations until February. 
In February and March, 1920 (fig. 56), Euthemisto was as generally distributed 
over the gulf and over Georges and Browns Banks, as it is in summer (fig. 55) ; but it was 
far less numerous, for it appeared at only about half the February and March stations 
(occasional examples only) , the only exception to this rule being the waters off south- 
ern Nova Scotia (not strictly within our limits), where it was taken in some numbers 
on two occasions (stations 20074 and 20075). Its numbers in the gulf fell to an even 
lower ebb in April, when we detected it (in very small numbers) at only 6 out of 30 
stations, a shrinkage due to an actual decrease in the stock and not to an emmigra- 
tion out of the gulf, for, as it happens, these few records were near Cape Elizabeth, 
on the one hand, and off the western shores of Nova Scotia, on the other, with no 
Euthemisto whatever taken at our stations farther out at sea during the month. 
In 1920 none were detected in the western side of the gulf in May (stations 
20120 to 20126), though a few (both bispinosa and compressa ) were taken off the 
seaward slope of Georges Bank on the 17th (station 20129), in a haul from 100-0 
meters; but in 1915 (which was also an earlier season in other respects) a scattering of 
Euthemisto was noted at most of the May and June stations at the mouth of Mas- 
sachusetts Bay, in the gulf generally outside the 100-meter contour, off Lurcher 
Shoal, on German and Browns Banks, and over the outer part of the continental 
shelf outside the continental edge off Shelburne, Nova Scotia. 89 During these months 
s« Recorded in my field notes from stations 10269, 10270, 10272, 10273, 10278, 10279, 10281, 10282, 10284, 10288, 10290, 10291, 10293, 
10294, 10296, and 10296. 
