142 BULLETIN OF THE BUREAU OF FISHERIES 
The young of the summer copepods never appear in large numbers, as in the 
case of winter breeders, and only three species—Acartia tonsa, Pseudodiaptomus 
coronatus, and Centropages typicus—were identified. 
The third summer group varies considerably in different seasons. If the 
prevailing winds through June, July, and August are from the south, great numbers 
of Gulf Stream forms may appear. Such was the case in 1922, and for that reason 
several species new to this coast were 
fade jae Sensis taken. The common annual visitors also 
Ves 2 Bostorducr sob wit dente 
Gd. 
& 
a 
Se 
Se 
TS. 
; Ws. 
B. n ‘ 
Fic. 39.—Occurrence of species of Acartia in sur- 
face collections from June to December, 1922. Fic. 40.—Occurrence of species of Acartiain surface collec- 
tions of 1923. —.—, Acartia tonsa; ———, A. bifilosa; 
——, Acartia tonsa; ------, , immature A. 
tonsa; —-—, A. bifilosa; —.—, A. clausii 
appeared in abundance. The southerly winds did not continue in the fall, however, 
and the result was that the usual tropical fish and ccelenterates were not observed at 
Katama Bay and in Vineyard Sound. 
No doubt these conditionsa ffected cope- 
, A. clausii; —-——, A. longiremus 
< . ° a ° ° . 
Bea ee aaa aS 5 
pods as well. As an illustration of this 
Ae Microsetella rosea appeared in great 
1a eg Be See ee 
Be SHE SEES 
asi 
ae 8. 
Se : : - 
4% ae 
aE + v.3 
Ne : ry 
Fic. 41.—Occurrence of Pseudodiaptomus coro- 
matus and Tortanus discaudata in surface col- Fic. 42.—Occurrence of Pseudodiaptomus coronatus and Tor- 
lections from June to December, 1922. : tanus discaudata in surface collections of 1923. ee 
P. coronatus; —.—, T. discaudata coronaius; ——.«—, T. discaudata. 
numbers on September 2 in vertical hauls taken off Block Island. Later during this - 
month (fig. 46, p. 145) scattering specimens were observed at Woods Hole. Much 
larger numbers would probably have been found here if hard south winds had 
