Vou.2]  Hsterly—Copepoda of the San Diego Region. 187 
less strongly developed hooked bristles than in the other species; 
inner ramus clearly with three joints, and with seven long 
bristles; bristles of first basal of the posterior maxillipeds and 
third joint of outer ramus of third swimming foot of usual form. 
Inner marginal bristle of second joint of outer ramus of fifth 
pair more slender, and inner marginals of first and second joints 
thicker than in the other species, distal border of second joint of 
outer ramus of ordinary form. 
4 Like female in structure of maxillipeds and terminal joint 
of outer ramus of third and fourth swimming feet. Fifth foot 
(figs. 406, c): right with stiff upright process on second basal 
(Inner margin), covered with stiff spines, second joint of outer 
ramus with a projection having four teeth at end. 
Length: Male, 3 mm. 
Occurrence: San Diego, June 23, 1904, one male. 
2. Genus Augaptilus. 
Hemicalanus (in part) Claus, 1863, p. 176. 
Augaptilus Giesbrecht, 1889, p. 3; 1892, pp. 65, 400, 724; 1898, 
p- 120. 
(See also T. Scott, 1893, p. 36, pl. 2, figs. 25-37; Steuer, 1904, 
p- 597.) 
2 Cephalothorax composed of five segments; rostral filaments 
short and sometimes feathered. Abdomen with 3 segments, geni- 
tal segment usually not wholly symmetrical. Anterior antennae 
25-jointed, outer ramus of posterior antennae rarely longer than 
the inner ramus. Mandibular blade with two teeth (mandible 
sometimes uniramous and with a stylet-like blade). Inner ramus 
of maxilla lacking; both maxillipeds with reduced proximal lobes 
and peculiarly equipped bristles (ef. fig. 410). Feet with spines 
on outer border of outer rami reduced in part, the third bristle 
on the inner border of the last joint of the outer ramus of the 
fifth foot not elongated, the inner marginal bristle of the middle 
joint awl-shaped or lacking; both rami 3-, rarely 2-jointed. 
& Sexual differences in the form of the abdomen, anterior 
antennae and fifth feet. Abdomen with 5 segments, genital open- 
ing right or left. The right or left anterior antenna may be the 
grasping organ. Rami of both feet of fifth pair 3-jointed (fig. 
41c, d). 
