Laguna Marine Laboratorp 121 
provided with a palp of five articles; mandibles have a palp of three 
articles. 
Thorax has first segment longer than those succeeding, but nar- 
rower; remaining segments subequal. Small epimera occur on all 
the segments at the antero-lateral angles. Legs all ambulatory ex- 
cepting the first pair, which are prehensile. Propodus of first pair 
very much expanded; its inferior margm has one long triangular 
process at the distal end, and one short process at the proximal end. 
Abdomen composed of two very short segments and one large ter- 
minal segment; latter is shghtly wider than long, 5 mm. by 4 mm., is 
narrower at posterior margin than at anterior. Post-lateral angles 
rounded, posterior margin produced medially into a sharp lobe 
between the uropoda. Uropoda about as long as terminal abdominal 
seement, 5 mm.; peduncle about as long as inner ramus; both rami 
end sharply. First pair of female pleopoda are attached close to- 
gether and are unsegmented. First and second pleopoda of male are 
modified. Second pleopoda of female are lacking. 
Ligyda occidentalis (Dana) 
(Figures 67 and 68) 
Locality—On the rocks at the high tide mark where they are very 
numerous, at Laguna Beach, California. 
Color—Sordid gray and brown; sometimes checkered in gray; 
legs tipped with orange. 
Body ovate and elongate, about two and a half times as long as 
wide, 22 mm. by 9 mm. Surface covered with granules. 
Head twice as wide as long with anterior and lateral margins 
rounded. Eyes very large, composite and elongate. First antenna 
very minute and rudimentary, composed of three articles. Second 
antenna measures 16 mm. First and second articles of peduncle 
subequal; third a little longer; fourth and fifth elongated; fifth longer 
and narrower than fourth; flagellum composed of thirty-one articles. 
Maxilliped has a palp of five articles. 
First four segments of thorax subequal and longer than those 
succeeding; last three have their post-lateral angles produced further 
than the preceding four. The epimera are united to the segments 
and are only faintly perceptible. Legs all ambulatory; have the 
dactylus bi-unguiculate. Propodus of first leg in male more dilated 
than that of the other legs and has a process on the inner distal 
margin in the male. Carpus and merus of first and second and third 
legs more dilated in male and have striated margins. 
First and second abdominal segments short and subequal. Sue- 
ceeding segments longer and narrower. Last abdominal longest and 
narrowest of all the abdominal segments. Its post-lateral angles are 
