278 bulletin: museum of comparative zoology. 



all other Salpae put together. And the few chains of S. confoederata 

 which were seen, or collected, it was nowhere abundant, were re- 

 stricted to Gulf Stream Stations (10071, 10076) and to the outer part 

 of the shelf (10070, 10073, 10074). Salpa tilesii, on the contrary, was 

 not taken at all at Stations 10064 and 10071, but was found in adulter- 

 ated Gulf Stream water at Station 10076, and was more or less com- 

 mon along the edge of the continental shelf (Stations 10061, 10070, 

 10077); and in the eastern part of the Gulf of Maine (Station 10096). 

 Salpae as a whole were far less numerous along the inner edge of the 

 Gulf Stream in July, 1913, than they were in July, 1908 (1909, p. 198), 

 when they were more abundant on the surface south of Nantucket 

 than I have ever seen them. 



The hyperiid amphipods. 



Hyperiid amphipods often form a large part of the macroplankton 

 in boreal waters and are of considerable importance as food for pelagic 

 fishes. The species so far captured in the Grampus hauls, all of which 

 are easily recognizable, are Hyperia viedusarum, Hyperia galba, Hype- 

 roche kroyeri, Parathcmisto oblivia, Euthemisto cornpressa, Euthemisto 

 bispinosa, Phronima atlantica, Phronima sedentaria, Tyro atlantica, 

 and Vibilia jcangerardi. Their occurrence, in the summer of 1913, 

 is shown in the following table (p. 279). 



(The identifications follow Bovallius, 1887-1889, and Sars, 1895. 

 For previous records off the New England coast, see Holmes, 1905, 

 and Rathbun, 1905). 



The most widely distributed hyperiids in the coast water, as well as 

 the most abundant numerically, were the two species of Euthemisto, 

 compressa and bispinosa (Fig. 68). This genus as a whole (the rela- 

 tionship of the two species to each other will be considered later) was 

 generally distributed over the Gulf of Maine (Stations 10058, 10087 

 to 10105); it was present on George's Bank (Station 10059), in the 

 waters over Nantucket Shoals (Station 10060), over the outer part of 

 the continental shelf, south of Block Island and Long Island (Stations 

 10062, 10063, 10065, 10066) ; and in the mixed water at the inner edge 

 of the Gulf Stream (Stations 10061, 10064, and 10076). But we did 

 not find it in Gulf Stream water proper (Station 10071, 10073), in 

 any of the tows in the comparatively fresh water off Chesapeake Bay 

 (Stations 10077 and 10078), or at any of the stations near shore be- 

 tween New York and the Chesapeake (Stations 10067, 10068, 10079- 

 10083), except in one instance (Station 10075). 



