242 BULLETIN OF THE BUREAU OF FISHERIES 



Harpacticus unireniis Kr0yer 



This harpacticoid becomes planktonic only occasionally or accidentally but nor- 

 mally lives on the bottom — according to Sars (1903-1911) on muddy bottom in 20 to 100 

 fathoms. The localities of capture which he quotes from various earlier authorities 

 include the Scottish coast, Norwegian coast, Spitzbergen, Bear Island, polar sea 

 north of Grinnell Land, and Bering Sea. Williams (1907) has also recorded it from 

 Narragansett Bay and from the brackish Charlestown Pond in Rhode Island, Fish 

 (1925) at Woods Hole, and the Canadian Arctic expedition collected it in surface 

 tows at two localities off southern Alaska (Willey, 1920). 



Doctor McMurrich, in his plankton lists, records this species occasionally at 

 St. Andrews in December (one haul) ; in five hauls between March 28 and May 19; 

 twice in June; not at all during the later summer or autumn; and Willey (1923) 

 reports it from the stomachs of winter flounders (Pseudopleuronectes) caught there. 

 In this region of violent tidal circulation it is perhaps swept up from the bottom by 

 the active stirring of the water. It has not been taken in the open Gulf and is hardly 

 to be expected there in the plankton. 



Heterorhabdus spinifrons (Claus) 



Dr. C. B. Wilson contributes the following note on this species, which "is easily 

 recognized by the asymmetry of the caudal rami and by the excessive length of one 

 of the apical seta? attached to the left ramus. In the plankton taken continuously 

 across the Atlantic by Herdman this species was found sparingly between mid-ocean 

 and the Canadian shore, and hence is found considerably north of the Gulf of Maine. 

 During the Challenger expedition it was taken at several widely separated stations 

 in the North Atlantic, and at one place in the South Atlantic from a depth of 2,650 

 fathoms (Brady, 1883). Thompson and Scott (1903) have reported it in the Medi- 

 terranean, in the Indian Ocean, and near Ceylon. Esterly (1905) obtained only a 

 single female of this species from the plankton at San Diego on the Pacific coast, 

 and incidentally one or two specimens of three other species of the genus. In the 

 Gulf of Maine it was obtained in only two vertical hauls — one in the open ocean 

 southeast of Georges Bank and the other outside of Boston Harbor. The first haul 

 was made on March 12, 1920, and this species had a percentage of four in the catch. 

 The second haul was made on May 4, 1920, and spinifrons formed only 1 per cent 

 of the catch. In none of the reports here enumerated was it found in any numbers, 

 and the four per cent mentioned [indicating an absolute abundance of about 3,100 

 per square meter] is about its maximum anywhere." 



In the Gulf of Maine it may be classed as an accidental visitor from warmer 

 and more oceanic waters offshore. 



Idya furcata (Baird) 



Sharpe (1911, p. 417) describes this as "perhaps the commonest and most 

 widely distributed of all the Harpactoida." Probably it will eventually prove 

 cosmopolitan in suitable situations, being recorded from widely separated localities 

 in the Arctic Ocean, including the Alaskan shore of Bering Strait and the Arctic 



