BIGELOW: COAST WATER EXPLORATION OF 1913. 321 
Although Pleurobrachia was widely distributed, it was by no means 
uniformly abundant. Its chief centre was from off New York (Sta- 
tions 10067, 10068) nearly to Cape May (Stations 10069, 10080), where 
-the deep water layers were filled with it, almost to the exclusion of 
other plankton (p. 269), extending for some twenty-five or thirty miles 
| Fic. 80.— Distribution of ctenophores, July—August, 1913. 
B, Beroe forskalii; 6, B. cucumis; m, Mnemiopsis leidyi; pe, Pleurobrachia 
pileus; P, P. pileus swarms. .., probable limit to P. swarms. 
, probable limit to Mnemiopsis in July. 
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| seaward (Stations 10072, 10070) beyond which their numbers rapidly 
decreased. It was still numerous when this region was passed again on 
| August 1, on our way north (Station 10082). South of Cape May it 
was much less common, and very few were taken over the shelf east 
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