ILaguna Ratine Laboratory 



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 margin 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 slightly 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 

 segment, 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 Laguua 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-ungniculate. 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. Suc- 

 ceeding segments longer and narrower. Last abdominal longest and 

 narrowest of all the abdominal segments. Its post-lateral angles are 



