COPEPODS OF THE WOODS HOLE REGION 39 



very short; exopod of second antenna with only six segments; fifth 

 legs uniramose, right one 2-segmented, left one 5-segmented, end seg- 

 ment shorter than either of the two preceding it, and tipped with two 

 minute, unequal spinules. Total length, 0.9-1 mm. 



Remarks. — This is one of our smallest calanoids, but it is widely 

 distributed ; it usually shows a decided preference for the surface but 

 may be found at any depth, even at the bottom in deep water. Its 

 small size would make it of little economic value in the food of adult 

 fishes, but Bigelow has called attention to the fact that the large 

 shoals found by the Gramyus in the shallows off Marthas Vineyard 

 may become of considerable importance in the diet of the young fishes 

 that congregate there. 



Genus CALOCALANUS Giesbrecht, 1888 



Head usually fused with the first segment; fifth segment rounded 

 posteriorly in the female, with sharp posterior corners in the male; 

 urosome 2- or 3-segmented in the female, 5-segmented in male ; caudal 

 rami armed with beautiful plumose setae, greatly enlarged; first 

 antennae reaching beyond the caudal rami, their basal segments with 

 enlarged plumose setae ; endopod of first legs 2-segmented, the other 

 rami of the first four pairs of legs 3-segmented ; fifth legs uniramose 

 in both sexes. 



KEY TO THE SPECIES (BOTH SEXES) 



1. Body stout, three times as long as wide ; caudal rami turned out- 

 ward at right angles to the body axis, each with four equal 

 plumes pave (p. 39) 



Body slender, four times us long as wide; caudal rami only 

 slightly divergent, inner plume of left ramus greatly en- 

 larged plumulosus (p. 41) 



CALOCALANUS PAVO (Dana) 

 FiGUEB 22 



Calanus pavo, Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 13, 1849. 

 Calocalanus pavo Gieskrecht, Fauna und Flora des Golfes von Neapel, vol. 19, 

 p. 185, pis. 1, 4, 9, 36, 1892. 



OccuiTence. — Numerous females were found by Wheeler at the sur- 

 face in the Gulf Stream south of Marthas Vineyard. 



Distrihutwn. — Cape Verde Island (Dana) ; tropical Atlantic and 

 Pacific (Giesbrecht) ; Canary Islands, Malta (Thompson) ; northern 

 Atlantic (Cleve) ; Adriatic (Steuer, Pesta) ; Mediterranean, Red Sea, 

 Indian Ocean (Thompson and Scott) ; Woods Hole (Wheeler, 

 Sharpe). 



