126 University of California Publications. [| ZooLocy 
First basal of fifth pair with coneave dentate inner border 
(fie: e). 
é Head not fused with thorax, anterior antennae straight ; 
outer ramus of right fifth foot without bristles on inner margin 
(fig. 1b), terminal bristles sometimes dentate, thorn-like. Basals 
and proximal joint of outer ramus of left foot (fig. 1c) elongate, 
terminal joint of outer ramus shortened. Outer ramus of right 
foot (excluding terminal bristle) reaches at most to the distal end 
of the second joint of the outer ramus of the left foot. Inner 
rami of both feet similar in structure. 
Coloration: Rather transparent, with variably distributed 
red pigment. In some eases this is found only in one of the 
anterior antennae, in others in the thorax and appendages, while 
the entire body of some animals is brightly colored. 
Leneth: Both sexes, 2.6-3.1 mm. 
Oceurrence: Probably the commonest species in the San 
Diego region, occurring abundantly in nearly all collections with 
the larger nets; in some eases C. finmarchicus is almost the only 
species, and is very often predominant. 
2. Calanus minor Claus. 
Cetochilus minor Claus, 1863, p. 172, pl. 26, figs. 1-8. 
Calanus valgus Brady, 1883, p. 33, pl. 3, figs. 1-7. 
Calanus minor Giesbrecht, 1892, p. 90, pl. 6, figs. 3, 16, 22; pl. 7, 
figs. 6-22; pl. 8, figs. 1, 9, 19, 30; 1898, p. 15. 
Calanus minor Wheeler, 1899, p. 165, fig. 2. 
Fig. 2.—Calanus minor. Female, lateral, X31. 
° Head fused with thorax, forehead and lateral edges of last 
thoracic segment rounded. Anterior antennae not as long as the 
body. Distal margin of second basal in second to fourth pairs 
of feet with a tooth; the proximal outer marginal spine of the 
terminal joint of the outer ramus, in the second to fourth pairs, 
respectively, divides the margin into portions as 5:4, 10:7, 2:1. 
Inner margin of first basal of fifth feet straight, more coarsely 
dentate than in C. finmarchicus. 
