156 BULLETIN OF THE BUREAU OF FISHERIES 



another at the outermost stations, between longitudes 71 and 65° and north of 

 latitude 39°, both in the earlier collections of the Bureau of Fisheries, reported on 

 by Hansen (1915), and during the more recent Gulf of Maine explorations, the latter 

 identified by Doctor Tattersall. 85 The combined list is as follows: Beniheuphausia 

 ambylops, Thysanopoda orientalis, Euphausia americana, E. mutica, E. brevis, E. 

 tenera, E. hemigibba, Stylocheiron carinatum, S. abbreviatum, Thysanoessa parva, 

 Nematoscelis atlantica, N. microps, and N. tenella. These are all oceanic species, 

 any of which may be expected to occur occasionally in the southeastern corner of 

 the gulf; hence a lookout should be kept for them in future collections from that 

 region. 



HYPERnD AMPHIPODS 

 Euthemisto 



The genus Euthemisto is one of the most characteristic, if not abundant, mem- 

 bers of the plankton of the offshore waters of the Gulf of Maine. How regularly 

 it is distributed there in summer (fig. 55) and over the shore banks as well appears 

 from the fact that it has been taken at at least 90 per cent of our stations outside 

 the immediate coastal zone, as bounded by the 100-meter contour on our July and 

 August cruises of 1912, 1913, 1914, 1915, and 1916. Inside this zone, on the con- 

 trary, it fails almost as regularly at this season, with only four or five summer records 

 for it from water shallower than 100 meters along the western side of the gulf. Simi- 

 larly, it is so rare at St. Andrews that it finds no place in Doctor McMurrich's local 

 plankton lists, and this is true, to a less extent, off western Nova Scotia as well, 

 judging from its irregular occurrence on German Bank. 



Euthemisto is usually only a minor factor in the plankton of the inner parts of 

 the gulf. This rule has its exceptions, however, for we encountered swarms of its 

 larvae off Penobscot Bay on August 11, 1913 (station 10090), and of adults as well 

 as young in the deep basin farther east (station 10092), while it was so plentiful in 

 the western basin on August 31, 1915 (station 10307), that the haul from 40 meters 

 yielded about 200 cubic centimeters of adults and multitudes of newly-hatched 

 larvae. 



We have usually found Euthemisto an important element in the tow nettings 

 at the mouth of the gulf and over the outer part of the continental shelf generally 

 from off Halifax to abreast of New York. For example, E. compressa abounded on 

 the south side of Nantucket Shoals on July 9, 1913 (station 10060), while young 

 bispinosa swarmed in the water southwest of Nantucket on August 22 of that same 

 year (station 10112). We took about 1,000 cubic centimeters of medium-sized 

 Euthemisto in a half hour's tow at 40 meters near Cape Sable on August 11, 1914 

 (station 10243), an equal volume of large specimens in a surface haul of the same 

 duration with a net 1 meter in diameter on Browns Bank, July 24. 1914 (station 

 10228), and 750 cubic centimeters on the surface off Shelburne, Nova Scotia, three 

 days later (station 10231). Euthemisto "again formed a considerable part of our 

 catches on the shelf south of Nova Scotia (stations 10291 to 10294), on Browns 

 Bank (station 10296), and off Marthas Vineyard (stations 10332 and 10333) in 



*> For the actual details of capture I refer the reader to Hansen (1915) and Bigelow (1917). 



