ond leg (fig. 11) has a long external spine that 

 extends beyond the distal margin of the second 

 exopodal segment. The fifth leg (fig. 12) con- 

 sists of a basal portion, common to both legs, 

 and a plate-shaped apical segment, which has 

 a long internal spine, a short, strong apical 

 spine, and a small external spine. An additional 

 small spine is located immediately lateral to 

 the apical spine. 



Scolecithricella dentata (Giesbrecht, 1892) 



Occurrence 



Sta. 5. 

 Sta. 15. 



(Plate 8, figs. 13-16) 



1 adult female, 1.48 mm. 

 1 adult female, 1.55 mm. 



Sta. 16. 1 adult female, 1.68 mm. 



Remarks 



The following characters mainly serve to 

 identify the female of this species: The pro- 

 some is nearly elliptical in dorsal aspect (fig. 

 13) ; its posterolateral margin in lateral aspect 

 (fig. 14) has a distinct incision that is also 

 clearly visible in dorsal view. The external spine 

 of the first exopodal segment of the second leg 

 (fig. 15) is long, slightly curved inward, and 

 reaches the distal margin of the second exopo- 

 dal segment. On the third exopodal segment of 

 the same leg, 3 small teeth lie along the exter- 

 nal margin immediately proximal to each of the 

 second and third external spines. The fifth leg 

 (fig. 16) is laminate and almost rectangular; 

 it has a tiny spine at the tip and a larger spine 

 on the internal margin. 



Scolecithricella ovata (Farran, 1905) 

 (Plate 8, figs. 17-21) 



Occurrence 



Sta. 5. 1 adult female, 1.98 mm. 

 Sta. 7. 1 adult female, 1.88 mm. 



Remarks 



The female of this species can easily be dis- 

 tinguished by the posterolateral margin of the 

 metasome, which has a distinct notch visible 

 in either lateral or dorsal view (figs. 17 and 

 18), and by the second and fifth pairs of legs. 

 The coxa of the -second leg (fig. 19) has a dis- 

 tinct notch on the external margin ; the roundly 

 produced internal margin also has a distinct 

 notch, in addition to a row of hairs and a seta. 



The fifth leg (fig. 20) is shaped like a paddle 

 with a cylindrical "handle" by which it is at- 

 tached to a common basal portion. The internal 

 margin of the paddle-shaped portion has a well- 

 developed spine. One specimen had a small sec- 

 ond internal spine close to the distal end of 

 the right leg (fig. 21). 



Scolecithricella vittata (Giesbrecht, 1892) 

 Occurrence 



Sta. 5. 2 adult females, 1.74 to 1.80 mm. 

 Remarks 



The female is readily recognized by the char- 

 acteri.stic fifth pair of legs. Figures of this and 

 other characters have been given by Grice 

 (1962). 



Scolecithricella auropecten (Giesbrecht, 1892) 

 (Plate 9, figs. 1-4) 



Occurrence 



Sta. 5. 9 adult females, 2.17 to 2.37 mm. 

 Sta. 7. 6 adult females, 2.11 to 2.34 mm. 

 Sta. 13. 1 adult female, 2.40 mm. 



Remarks 



The female of this species can be identified 

 easily by the posterolateral margin of the meta- 

 some, which in latei'al view has a round de- 

 pression (fig. 1), and by the fifth pair of legs 

 (fig. 2). Figures of the mouth parts and the 

 swimming legs have been given by Rose (1942) 

 and Giesbrecht (1892). 



Two specimens possessed abnormal fifth pairs 

 of legs (figs. 3 and 4) but appeared to be 

 identical with the normal specimens in all other 

 details. 



FAMILY METRIDIIDAE 



Metridia lucetis Boeck, 1865 

 Occurrence 



Sta. 16. 2 adult females, 2.68 to 2.78 mm. ; 

 9 fifth copepodid females, 1.90 to 



2.07 mm. ; 

 4 fifth copepodid males, 1.73 to 

 1.84 mm. 



Remarks 



This species is easily recognized by two char- 

 acters. The posterolateral margin of the met- 



CALANOID COPEPODS FROM NORTH PACIFIC 



555 



