PLANKTON OF THE WOODS HOLE REGION 
129 
Mnemiopsis leidyi appears in smaller numbers at Woods Hole. In Long 
Island Sound there is a very large fall maximum in August and a large winter 
maximum in December and January. They are rarely found in Buzzards Bay in 
large numbers, and were taken in only 3 years during the 15 for which the author 
has records. During the past year a single specimen appeared on December 11 
and three on December 15. Cape Cod is, no doubt, the northern limit of this 
species, and its appearance in local waters depends upon the winds. Specimens 
taken this spring were stragglers from the winter maximum of more southern 
waters. No remnants of the fall maximum found their way into Great Harbor in 
1922 (figs. 27, 28, and 32). 
Bolina alata has been taken at Woods Hole in September by Mr. Edwards. 
Agassiz described it as being one of the commonest species in Massachusetts Bay, 
but rare south of Cape Cod. None was seen in Great Harbor during the past year. 
Beroe cucumis is usually very rare in this region, although Mr. Gray found it 
abundant on one or two occasions in late April and May. It is a northern form 
J3 
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o. 
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o 
o 
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1893 
1906 
1 
1907 
1 
■ 
■ 
1908 
H 
Fig. 32. — Occurrence of Mnemiopsis leidyi during successive years, 1893 to 1908 
whose appearance in local waters is accidental, depending upon strong easterly 
winds. 
The following coelenterates appeared during the years 1922 and 1923: 
Hydromedusae : 
Bougain villia carolinensis 
(McCrady). 
B. superciliaris, Agassiz. 
Dipurena strangulata, McCrady. 
Ectopleura ochracea, Agassiz. 
Gemmaria cladophora, Agassiz. 
Hybojodon prolifer, Agassiz. 
Lizzia grata, Agassiz. 
Melicertum campanula, Agassiz. 
Obelia sp. 
Podocoryne carnea, Sars. 
P. fulgurans (Agassiz). 
Stomotoca apicata (McCrady). 
Hydromedusse — Continued. 
Syncoryne mirabilis, Agassiz. 
S. producta, Hargitt. 
Tiaropsis diademata, Agassiz. 
Turritopsis nutricula, McCrady. 
ScyphomedusEe : 
Aurelia flavidula, Peron and Lesueur. 
Cyanea capillata, Eschscholtz. 
Dactylometra quinquecirra (Desor). 
Ctenophora: 
Mnemiopsis leidyi, Agassiz. 
Pleurbrachia pileus (Fabricius) 
