BIGELOW: EXPLORATIONS IN THE GULF OF MAINE. 125 



swarms. The greatest number of Cyaneas were at Station 14 and in 

 Penobscot Bay (Station 21a). 



As Damas has pointed out (Helland Hansen and Nansen; 1909, pt. 1, 

 p. 101) Cyanea is one of the most important index-speeies of the larger 

 plankton, because its attached stage lives in shallow water; conse- 

 quently wherever Cyaneas are found off shore, it shows that there is a 

 considerable admixture of coast water, and the same is true of Aurelia. 

 Our data is important as showing that neither of them is general 

 over the Gulf; both seem, if not absolutely, at least chiefly limited to 

 a rather narrow coast-band all around the Gulf, even more so than 

 Staurophora. And this fact suggests that there is comparatively 

 little mixing of offshore and coast water in August. In early July as 

 pointed out (p. 62), there is a pronounced fresh tongue off Cape Ann; 

 but this flow of coast water probably reaches its maximum in June, 

 when the Aurelias and Cyaneas are still very small, or perhaps even 

 before they are set free. 



Phialidium languidum affords another example of the distribution of 

 a neritic species. It was taken at Stations 22, 24, 25, 31, 32, 38, 40, 

 41, 42, 43, and in all the harbors and bays, especially Kittery, Winter 

 Harbor and the Kennebec River; and also near Gloucester. These 

 records show that it w T as found further off shore than either Aurelia 

 or Cyanea, i. e., near Piatt's Bank (Station 24) and on Jeffrey's Bank 

 (Station 25). But we did not find it on our run across the Eastern 

 Basin toward Nova Scotia, nor on German Bank; meeting it again 

 at Station 31 and 32, but not at Station 36. It swarmed at Station 32 

 and Station 40, on the surface, the salinity and temperature being: — 



Station 32 surface temperature 57° salinity 32.5 < %o 



Station 40 surface temperature 58° salinity about 32% 



It was abundant in the harbors with lower salinity. 



Much more strictly confined to the coast water is the medusa 

 Melicertum campanula, which attains sexual maturity at just the time 

 of our cruise. Great swarms were met with in Kittery Harbor, 

 July 12 and 23, many in Gloucester and in Rockport Harbor, July 

 9-12; but the only outside stations at which it was taken were Nos. 

 4, 8, 12, 14, 22, none of them over ten miles from land. In past years, 

 likewise, I found it very common in Penobscot Bay and at Grand 

 Manan: but all its records in the Gulf are close to shore. 



Siphonophores. — Only two species of siphonophores, Agalma elegans 

 and Physophora hydrostatica, were taken on the cruise; but their few 

 occurrences are worth special notice because they are typical oceanic 



