PLANKTON OF THE WOODS HOLE REGION 127 
Cyanea capillata appears commonly in spring and fall, but not in as great 
numbers as Aurelia. On April 14, 1923, the first specimen appeared. Throughout 
May and early June specimens varying from 10 to 50 mm. could be seen daily at 
the surface in Great Harbor, often in large numbers. Alexander Agassiz observed 
great numbers of Cyanea at the surface between 4 and 5 a. m. at Provincetown. 
“By 7 a. m. all had returned to deeper waters, although not a breath of air had 
disturbed the surface.’’ A variation in abundance was clearly noticeable in local 
waters during the past year, but the vertical migration did not affect the whole 
group, Some specimens occurring at the surface throughout the day. Their numbers 
increased rapidly, however, during the flood tide. It may be that Agassiz’s observa- 
1698 
1699 | 
1900 } 
1901 
1902 
1903 | 
1904 | 
1905 |_| 
1906 
1907 
Fig. 30.—Occurrence of Cyanea capillata during successive years, 1893 to 1907 
tions could be explained on that basis. Unfortunately no records of the tide were 
given. 
Dactylometra quinquecirra occurs occasionally in Vineyard Sound and Buzzards 
Bay, although in very small numbers. In Narragansett Bay it is usually very 
abundant in September and October. On August 8, 1923, a single specimen was 
taken in Lackeys Bay, and several days later a few were observed in Vineyard 
Sound. George Gray records large numbers taken on several occasions, together 
with Salpa democratica-mucronata, off Nonamesset Island at the mouth of Great 
Harbor. This species is known to be nocturnal, and for this reason the local appear- 
ance may be greater than the records indicate because very little night collecting - 
