VoL.2]  Hsterly—Copepoda of the San Diego Region. 183 
1. This joint in third pair broad and oval, terminal bristle short- 
Med (OA SEO) imeers aa ctersie ssh lcr sce si ctw lens ouckelere velo enersts eo ters lo are eels fel 2 
2. First basal of posterior maxilliped with a very long, heavy 
bristle in the middle of the inner border; rostral papilla with 
2 [oonini; (i, BiWMeso60cc0s0ccns00end suo5ad0asGon abe H. spinifrons 
2. As above, but rostral papilla without point (figs. 38), ¢)........ 3 
3.2 Inner marginal bristle of second joint of inner ramus of fifth 
foot much shorter and more slender than those of the third 
joint; first joint of outer ramus with thorn-like inner marginal 
Jorenisiiel, 25 Iivorisay stovare (ites GE). 66 oacnaocehecccsneaease H. clausi 
3.9 Inner marginal of second joint of inner ramus of fifth foot but 
little shorter than those of third joint; first joint of outer 
ramus without inner marginal bristles............... H. papilliger 
1. Heterorhabdus spinifrons Claus. 
Heterochaeta spinifrons Claus, 1863, p. 182, pl. 32, figs. 8-9, 
14, 16. 
Heterochaeta spinifrons Giesbrecht, 1892, pp. 372, 382, pl. 10, 
figs. 1, 3, 11, 16, 19, 31; pl. 39; figs. 42, 43, 51, 52, 54. 
Heterorhabdus spinifrons Giesbrecht, 1898, p. 114. 
Fig. 37.—Heterorhabdus spinifrons. Female. (a) Head, lateral, X83. (6) 
Posterior maxilliped 167. 8.1, first basal. 
The papilla on front of head ends in a sharp point; anterior 
antennae reach beyond the end of the furea by the last four or 
five joints. The fourth lobe of the anterior maxilliped has two long, 
thick bristles, and a small, slender one which is hardly 14 as long 
as the other two; the fifth lobe has two bristles, one of which 
is longer and thicker than the other. A spine-like bristle at the 
end of the inner margin of the first basal of the posterior maxil- 
liped is 14 the length of the long bristle in the middle of the 
margin (fig. 370). Hooks at the end of both outer rami of the 
