268 
BULLETIN OF THE BUREAU OF FISHERIES 
Cautioning the reader that the difference may be partly explicable as evidence 
of “rich” and “poor” years for the species, the percentages indicate that it is prac- 
tically universal in the inner half of the gulf throughout the summer and early 
autumn but less plentiful during winter and spring. The average number per 
square meter likewise shows it to be most abundant in the inner part of the gulf 
during the warm months. 
The average numbers of P. parvus per square meter in vertical hauls, counting 
only the stations where it occurred, are as follows: 
Date 
Average 
number 
Date 
Average 
number 
455 
August, 1915 
14, 042 
4,065 
9,045 
600 
September, 1915 
3, 656 
1, 015 
October, 1915 
June, 1915 
If the table were made to include the stations where it was absent, or at least so 
rare that the vertical net failed to take it, the discrepancy between March and April 
and the other months would be still greater. The hauls for February, 1920 (sta- 
tions 20044 to 20048) , are omitted from this table because the high average resulting 
from them (about 2,000 per square meter) is due to catches of 5,000 and 3,000 per 
square meter at the two stations outside the continental edge (stations 20044 and 
20045), which would undoubtedly be several times too high for the inner waters of 
the gulf at this season. 
In the western side of the basin Paracalanus increased in number in 1915 from 
about 1,000 per square meter on May 5 (station 10267) and 1,300 on June 26 (station 
10299) to 16,100 on August 31 (station 10307). 
In the eastern side of the basin where there were only about 1,100 Paracalanus on 
June 19 (station 10288) the vertical haul took 23,450 per square meter on August 6 
(station 10304). On September 29 there were 850 per square meter at a station in 
Massachusetts Bay (10320), and the number had risen to about 14,000 by October 
27 (mean of stations 10338 and 10339). A change of the opposite order at a neigh- 
boring location near Gloucester, where the number per square meter declined from 
more than 25,000 on May 4 (station 10266) to about 2,500 on August 31 (station 
10306) and about 3,000 on October 1 (station 10324), shows how the formation and 
dispersal of local shoals may more than offset the general seasonal augmentation of 
the species at any particular locality. 
Off the Isles of Shoals a slight decrease took place from 5,250 per square meter on 
May 14 (station 10278) to 3,170 on October 4 (station 10325); on German Bank the 
figure remained about stationary from May 7 (1,500 per square meter at station 10271) 
to June 19 (1,500 at station 10290) and September 2 (1,600 at station 10311). 
Notwithstanding these irregularities, not one of the October stations yielded less 
than 2,000 P. parvus per square meter, and the maxima within the gulf were much 
greater in October (30,750 off Cape Cod, station 10336, and 24,450 in Massachusetts 
Bay, station 10338) than in September (6,650 per square meter, station 10319). 
Thus it seems that there are actually more P. parvus in the gulf in mid-autumn than 
