79° CHARLES BRANCH WILSON 
one margin only; two pairs of maxillae and a pair of maxillipeds. One pair 
of swimming legs on the cephalothorax, biramose and the rami heavily armed 
with setae. 
Generic characters of male. Male a pigmy attached to the genital 
segment or the egg strings of the female. Body cyclopoid, tapered posteriorly. 
Head and first thorax segment fused, second, third, fourth, and fifth segments 
distinct; abdomen three-jointed. First antennae cylindrical, five-jointed; second 
pair prehensile with stout claws on the basal joint; two pairs of maxillae and 
a pair of maxillipeds. Four pairs of biramose swimming legs, all the rami two- 
jointed and heavily armed with setae; fifth pair rudimentary. Anal laminae 
armed with very long plumose setae. 
(Juanettia, from the name of the island where the specimens were ob- 
tained.) 
Remarks. This genus is closely related to the Chondracanthidae, but 
differs in such important particulars from any of the genera in that family that 
it can hardly be classed with them. The upper and lower lips do not form 
a sucking tube but project from the ventral surface in a manner similar to 
that found in the Zyrgasz/zdae. The first antennae are somewhat similar to 
those of the Chondracanthidae, but the second pair in the male have the pre- 
hensile claws on the basal joint instead of terminal. The mandibles are shaped 
like those of the Lernacopodidae, and are toothed along one margin only. 
Both sexes have a pair of well developed maxillipeds very different from those 
found in the Chondracanthidae. The female has a single pair of biramose 
swimming legs on the cephalothorax, while the male has four pairs fully devel- 
oped and a fifth pair rudimentary. These differences are too important to 
allow the genus to be placed with the Chondracanthids and for the present it 
must constitute a family by itself. 
Juanettia cornifera, new species. 
Host and record of specimens. Three mature females, each with egg 
strings and with one or more attached males, were taken from the gills of the 
whitespotted cabrilla, Paralabrax (Serranus) humeralis, at Juan Fernandez 
(Masatierra) Dec. 16, 1916. They are made the types of the new species 
and genus. 
Specific characters of the female. In addition to the generic charac- 
ters the following may be noted. First antennae attached on the dorsal sur- 
face of the head at the anterior margin; basal portion fleshy and very indis- 
tinctly segmented, terminal portion abruptly narrowed and distinctly segmented. 
Second antennae one-jointed prehensile claws, attached to the ventral surface 
near the anterior margin. The mouth and mouth parts project from the ventral 
surface of the head in the form of a broad cone. The upper lip at its base 
