asome is produced into a point. In the second 

 leg, the basis has a hooli on the distal margin 

 and the internal margin of the first endopodal 

 segment is proximally provided with a deep 

 invagination guarded by 3 strong teeth. 



Brodsky (1950) distinguished the Pacific 

 form of Metridia lucens from the Atlantic form 

 and gave it a new name, Metridia pacifica. 

 Damkaer (1964 and personal communication) 

 examined specimens from both the Pacific and 

 the Atlantic and found no morphological dif- 

 ferences to warrant two species. 



FAMILY CENTROPAGIDAE 



Centropages hradyi Wheeler, 1900 

 Occurrence 



Sta. 5. 1 adult female, 1.95 mm. 



Sta. 9. 1 adult male, 1.74 mm. 



Sta. 13. 30 adult females, 1.91 to 2.08 mm. ; 



8 adult males, 1.78 to 1.91 mm. 

 Sta. 15. 11 adult females, 2.00 to 2.24 mm. ; 

 2 adult males, 1.97 to 2.00 mm. 



Remarks 



This species is characterized by the rounded 

 posterolateral corners of the metasome, the 

 symmetrical genital segment, and the large 

 caudal rami, each of which has a fingerlike 

 projection between the two lateral terminal 

 setae. 



Centropages elongatns Giesbrecht, 1896 

 Occurrence 



Sta. 3. 7 adult females, 1.74 to 1.90 mm.; 



7 adult males, 1.65 to 1.80 mm. 

 Sta. 5. 1 adult female, 1.91 mm. 

 Sta. 7. 1 adult female, 1.91 mm.; 

 1 adult male, 1.81 mm. 



Remarks 



The present specimens are in agreement with 

 the figures given by Grice (1962). 



Centropages violaceus (Claus, 1863) 

 (Plate 9, figs. 5-11) 



Occurrence 



Sta. 3. 1 adult female, 2.17 mm. ; 



4 adult males, 2.04 to 2.11 mm. 

 Sta. 5. 3 adult females, 2.11 to 2.14 mm.; 



4 adult males, 2.04 to 2.17 mm. 



Sta. 7. 11 adult females, 2.14 to 2.24 mm. ; 

 2 adult males, 2.14 to 2.17 mm. 



Remarks 



The female of this species can be distin- 

 guished by the genital segment, which in dorsal 

 aspect (fig. 5) is slightly asymmetrical — the 

 right side is slightly more swollen. The swell- 

 ings of both the right and left sides have a 

 group of spinules (figs. 6 and 7). The second 

 urosomal segment ventrally lacks the knoblike 

 projection shown in the figure by Giesbrecht 

 (1892). In the fifth leg (fig. 8) the spiniform 

 projection of the second exopodal segment is 

 slightly shorter than the third exopodal seg- 

 ment and has a row of stiff hairs along the 

 internal distal margin. 



The male of this species can be identified by 

 the fifth pair of legs (figs. 9-11). The second 

 exopodal segment of the right leg is nearly 

 elliptical ; the spinous projection of the segment 

 bends sharply outward. The terminal claw has 

 a deep notch at the proximal portion of the 

 internal margin ; in this notch is an acute tooth. 



Centropages elegans Giesbrecht, 1895 

 (Plate 9, figs. 12-26; plate 10, figs. 1-6) 



Centropages elegans Giesbrecht, 1895, p. 256, 

 plate 4, figs. 1-2. 



Occurrence 



Sta. 3. 21 adult females, 1.86 to 2.04 mm.; 



10 adult males, 1.84 to 1.97 mm. 

 Sta. 5. 16 adult females, 1.94 to 2.14 mm. ; 



9 adult males, 1.84 to 2.01 mm. 

 Sta. 7. 3 adult females, 2.01 to 2.07 mm. ; 



4 adult males, 1.94 to 2.04 mm. 



Description of Female 



The total length of the specimens ranges from 

 1.86 to 2.14 mm. The prosome is about three 

 times as long as the urosome. The cephalosome 

 in dorsal aspect has a small semicircular pro- 

 jection at the tip and a knoblike process at the 

 posterodorsal margin (plate 9, fig. 12). The 

 first metasomal segment is incompletely sepa- 

 rated from the cephalosome — a line of joint is 

 visible only on the dorsal region. The postero- 

 lateral margins of the metasome are smoothly 

 rounded. 



The urosome (plate 9, figs. 13-15) is 3-seg- 

 mented ; the segments and the caudal rami have 



CALANOID COPEPODS FROM NORTH PACIFIC 



557 



