COPEPODS OF THE WOODS HOLE REGION 



165 



spiniiles across their dorsal posterior margins; end segment of fifth 

 legs short and stout, swollen at its base and acute di stall y, where it is 

 armed with a fringe of short hairs along the outer margin, but with- 

 out teeth. Total length, 1.15-1.25 mm. 



Male. — Body shorter and narrower than in the female, but with 

 the urosome relatively longer and armed with similar dorsal spi- 

 nules; end segment of right fifth leg narrow, strongly curved and 

 armed with three or four small spines along its outer margin; end 

 segment of left leg very small and tipped with a finger process and 

 a short spine. Total length, 1-1.1 mm. 



Remarks. — Bigelow found this species in the Gulf of Maine aver- 

 aging a larger percentage in the shallow waters along shore than in 

 deeper parts, but it does not attain sufficient abundance to constitute 

 an important food suppl3\ Farther south in Chesapeake Bay it oc- 

 curs in exceptional abundance, and shows there the same ability for 

 ready adaptation to differing 

 degrees of salinity that is ex- 

 hibited here by tonsa. 



ACARTIA LONGIREMIS (Lilljeborg) 



Figure 113 



Dlas longiremis Lilljb30rg, De 



crustaceis ex ordinibus tribus : 



Cladocera, Ostracoda et Cope- 



poda, in Scania occurrentibiis, 



p. 181, pi. 24, 185.3. 

 Acartia longiremis G. O. Sars, 



Crustacea of Norway, vol. 4, p. 



149, pis. 99, 100, 1903. 

 Occurrence. — Both sexes in 

 surface tow from Bureau of 

 Fisheries wharf, August, 1923 ; 

 obtained by Bigelow in sur- 

 face tow, Station 10331, Gram- 



fUS. 



Distribution. — Faroe Is- 

 lands, North Sea, Skager Rak 

 (Cleve) ; Baltic Sea (Mobius) ; Gulf of Finland (Nordquist) ; north- 

 ern Atlantic (Cleve) ; English seas (Brady, T. Scott) ; Mediterra- 

 nean (Thompson and Scott) ; Norwegian coast (Sars) ; North Sea 

 (van Breemen) ; Greenland (Stephensen) ; Arctic Ocean (Mriizek. 

 Willey) ; Kieler Fohrde (Giesbrecht) ; Chesapeake Bay (Wilson) ; 

 Gulf of Maine (Bigelow) ; Woods Hole (Fish). 



Color. — Body extremely transparent, with a faint tinge of blue, 

 enough to make it visible over either a white or a black background. 



Female. — Metasome three times as long as wide, narrowed and 

 obtusely truncated anteriorly; no tentacular filaments; corners of fifth 



Figure 113. — Acartia longiremis: a. Female, 

 dorsal (after Giesbrecht) ; 6, male, fifth 

 logs ; c, femfile, fifth legs 



