142 
BULLETIN OF THE BUEEAU OF FISHERIES 
The young of the sximmer 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 
^ i ^ i i i I taken. The common annual visitors also 
Fig. 39.— Occurrence of species of Acartia in sur- 
face collections from June to December, 1922. Fig. 40.— Occurrence of species of Acartia in surface coUec- 
, Acariia ionsa: , immature A. tions of 1923. — . — , Acartia tonsa; , A. bifllosa; 
tonsa: , A. bifilosa: — . — , A. dausii , A. clausii; — . , A. longiremns 
appeared in abundance. The southerly winds did not continue in the fall, however,, 
and the result was that the usual tropical fish and coelenterates were not observed at 
Katama Bay and in Vineyard Sound. 
I I I f o II No doubt these conditionsa ffected cope- 
FlG. 41. — Occurrence of Pseudodiaptomus coro- 
natus and Tortanus discaudata in surface col- Fig. 42.— Occurrence of Pseudodiaptomus coronatus and Tor- 
lections from June to December, 1922. , tanus discaudata in surface collections of 1923. P. 
P. coronatus: . , T. discaudata ' coronatus: — . — , 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 woiild probably have been found here if hard south winds had 
