9 
two hinder teeth only are on the carapace, and are longer, but not highes than 
the others; outer maxillipeds reaching to the tip of the movable scale of outer 
antenne; hands of first pair small and slender. The most noticeable charac- 
teristic of this species is the presence of eight longitudinal lines of a tint 
lighter than the ground color of the body. Upon the carapace these eight 
lines become broken up, and mingled with other markings, producing a pattern 
resembling that of watered silk. Two dried specimens from San Diego, 
collected between tides, and one larger one, in alcohol, presented by Henry 
Edwards. 
Length of largest specimen, from tip of rostrum to end of abdomen, 2% 
inches. 
Idotea rectilinea. 
Body, slender; not increasing in width backwards; all the segments of the 
thorax equal in width, and the abdomen rectilinear, nearly as wide as the 
thorax; first two segments of abdomen, distinct; total length of abdomen 
about equal to that of last three thoracic segments; posterior extremity 
obtusely pointed. Thoracic segments equal in length. Outer antennae, 
jong; the peduncle equal in length to the three first segments of body; 
flagellum broken in both specimens. Color, various; one dried specimen 
almost entirely black, the other with a black line down centre of body, the 
rest of which is yellowish. 
Length, 0.80 inch. Width, 0.17 inch. San Diego. 
Serolis carinatus. 
Thorax and abdomen conspicuously keeled upon the centre of every seg- 
ment; the first segment slightly waved on its posterior margin, the curve of 
the segments increasing rapidly, in such a manner that the last entirely en- 
closes the free abdominal segments on their sides. Caudal segment rounded 
at the extremity, with two marginal teeth on each side, at a considerable dis- 
tance from the extremity, the central carina running the entire length of the 
segment; last basal joint of inner antennz longer than the flagellum; flagel- 
lum of outer antennze much shorter than either of the two of the preceding 
basal joints, and last basal joint about equal in length to the penultimate. 
Eyes large, reniform, conspicuous. The texture of the upper surface of a 
dricd specimen, under a two-thirds power, has a somewhat squamate appear- 
ance. Color, a grayish brown, diversified with dots and irregular markings 
of black; hands long and slender; dactylos equal in length to the manus. 
Two specimens from San Diego. Length, 0.21 inches; width, 0.16 inches. 
