32 



BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



Male. — Head bluntly rounded anteriorly; genital segment a trifle 

 wider than long; urosome 5-segmented; left caudal ramus wider and 

 longer than the right, its second inner seta elongated; both fifth 

 legs present, the tip of the right leg just reaching the distal end of 

 the second segment of the left leg. Total length, 3.75-5 mm. 



Reinarhs. — This species has been reported from the Atlantic as 

 far north as latitude 61° N. Bigelow found it to be fairly common 

 in the Gulf of Maine, but nowhere abundant, and hence not possess- 

 ing much economic importance. He characterized it as a " rare 

 stray " from the warmer and saltier portions of the Atlantic outside 

 of the continental edge. Hence its appearance in the pre,sent area 

 will be more or less accidental and probably in comparatively small 

 numbers. 



EUCALANUS ATTENUATUS (Dana) 



Figure 16 



Calanus attenuatus Dana, Proc. Amer. Acad. Arts, and ScL, vol. 2, p. 18, 1849. 

 Eucalanus attenuatus Giesbrecht and Schmeox, Das Tierreich, Lief. 6, Cope- 

 poda, p. 20, 1898. 



Occw^ence. — Three females from trawl wings at Stations 2195, 

 2219, Albatross, south of Nantucket. 



Distribution. — ^Western Mediterra- 

 nean (Giesbrecht) ; Messina and Nizza 

 (Glaus) ; Eed Sea, Indian Ocean 

 (Thompson and Scott) ; Malay Archi- 

 pelago (Dana, Cleve) ; Kingsmill Is- 

 land, China Sea (Dana) ; off Nova 

 Scotia (Willey); Gulf of Maine 

 (Bigelow) ; tropical Atlantic and 

 Pacific (Giesbrecht). 



Color. — Transparent with a variable 

 degree of red pigment irregularly and 

 often very asymmetrically distributed 

 in the body, some of the basal segments 

 of the first antennae, and the terminal 

 segments of the appendages. The 

 plumes at the tips of the first antennae 

 are usually bright orange with a bluish 

 or violet iridescence. 



Female. — Head triangular with an 

 indentation on either side of the 

 frontal margin, strongly narrowing the part in front of it ; fifth seg- 

 ment rounded at the jDosterior corners; genital segment longer than 

 wide; urosome 3-segmented; caudal rami symmetrical, second inner 

 seta of left ramus elongated ; proximal segment of endopod of second 

 antenna four times as long as wide and one-third longer than the 

 distal segment. Total length, 4^5 mm. 



FiGUKB 16. — Eucalanus attenuatus: 

 a. Female, dorsal ; C, fifth legs of 

 male 



