Vou.2] Esterly—Copepoda of the San Diego Region. 141 
First joint of inner ramus of maxilla with two bristles on ante- 
rior face. Third lobe of second basal of posterior maxilliped with 
two bristles. Inner margin of first basal of the fourth pair of 
feet ends in one or two points (fig. 12a) ; anterior and posterior 
faces of first basal of second to fourth pairs set with hairs and 
spines; surfaces of first and second joints of outer ramus of the 
third pair and of second joint of the fourth, naked. Fifth foot 
rudimentary, symmetrical. 
4 Fifth foot asymmetrical (fig. 12e); compare also generie¢ 
description. 
Coloration: Rather transparent, with red pigment in varying 
amounts and distribution, never very abundant. 
Length: Both sexes within 0.8-1.2 mm. 
Occurrence: Fairly common in hauls with smaller nets, both 
sexes being present summer and winter. 
Sub-fam. CLAUSOCALANINAE. 
Clausocalanina Giesbrecht, 1892, p. 49. 
@ Head usually fused with the first thoracic segment, fourth 
thoracic always fused with the fifth; rostrum ends in two short, 
soft filaments or is lacking; abdomen with four segments, furea 
symmetrical. Eighth and ninth joints of anterior antennae 
fused ; terminal joint short, seldom fused with the preceding one. 
Outer ramus of posterior antennae 6-jointed and always longer 
than the inner ramus. The other appendages of the head for the 
most part as in Calanus. Inner ramus of the first pair of feet 1- 
jointed, of the second pair 2-jointed, of the third and fourth 3- 
jointed; terminal bristle of the outer rami with dentate border ; 
third joint of outer ramus in second to fourth pairs with three 
bristles on outer border. Fifth pair rudimentary on each side, 
3-jointed or lacking. 
& Unknown in Spinocalanus and Ctenocalanus. Abdomen 
with shortened anal segment; anterior antennae and head 
appendages in some eases like those of the female, in others as in 
the Paracalaninac. Fifth pair of feet: the right, 1- to 5-, the left 
5- jointed. 
