78 



BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



merits of abdomen equal, each twice as long as the anal segment; 



fifth legs 3-segmented, the two free segments usually more or less 



completely fused and armed with three spines, one terminal, of 



moderate length and smooth, one on 

 the inner margin, the longest of the 

 three and setose distally, and one on 

 the outer margin, smooth and very 

 small. Total length, 3.7-5.25 mm. 



Male. — No frontal crest; posterior 

 corners of fifth segment smoothly 

 rounded; anal segment much shorter 

 than in the female; fifth legs scarcely 

 reaching the middle of the first abdom- 

 inal segment; basipods of left fifth 

 leg long and cylindrical, the rami 

 3-segmented and about equal; second 

 basipod of right leg enlarged proxi- 

 mally, e n d o p o d 1 -segmented, awl- 

 shaped, and attached to the enlarged 

 base of the second basipod; exopod 

 3-segmented, attached to distal end of 

 basipod. Total length, 4.5^.75 mm. 



Remarks. — This handsome calanoid, 

 as pointed out by Sars, is a true arctic 

 species and is found most abundantly 

 in the far north, but it also occurs in 

 the deeper waters of other oceans, even 

 in the Tropics, and hence would nat- 

 urally be expected in the Woods Hole 

 area. The frontal crest of the female 



Figure 52.—scapiiocaianu8 mag- ^nd the fifth legs of both sexes are the 



nus: a, Female, fifth legs; ^, ■, , ■, , % --t j-n a- 



male, fifth legs ; c, female, dorsal best characters tor identification. 



SCAPHOCALANUS VALIDUS (Farran) 



Figure 53 



Soolecithrix valida Faeban, Rep. Fisheries Ireland, 1906, pt. 2, p. 55, pi. 5. 



fig. 14, pi. 6, fig. 7, 1908. 

 Scaphocalanus validns With, Danish 7nfifoZ/-Expedition, vol. 3, pt. 4, Copepoda 1, 



p. 198, fig. 62, a-f, pi. 7, fig. 11, a-b, 1915. 



Occurrence. — A male and a female from the trawl wings, Station 

 994, Fish Hawk, south of Marthas Vineyard. 



Distribution. — North Atlantic, Irish coast (Farran) ; Malay 

 Archipelago (A. Scott) ; between Scotland and Iceland (With). 



Color. — Nothing is known of the color of the living copepod. 



