Vol. XXIX, pp. 157-160 September 6, 1916 



PROCEEDINGS 



OK THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



DESCRIPTIONS OF THREE NEW SPECIES OF AMPHI- 

 PODS FROM SOUTHERN CALIFORNIA. 



BY C. R. SHOEMAKER. 



In a large collection of Crustaceans from the Venice Marine 

 Biological Station, of Los Angeles County, California, sent to the 

 U. S. National Museum for determination, the following new 

 species of Amphipods were found. 



Family Lysianassid^. 

 Aruga macromerus new species. 



This species, which is represented by a single male specimen, does not 

 agree in a few minute details with Holmes' genus Aruga, but these 

 differences do not seem to me of enough importance for the creation of a 

 now genus. There are a few small setae at the distal end of the inner 

 plate of the first maxillae. Plates of the second maxillae are not particu- 

 larly narrow. 



Eyes large, oval, and black. Lateral lobes of the head with front 

 margin slightly curved and bearing a few minute setules, anterior angle 

 rounding. First antennae with first joint robust; second and third much 

 smaller. Flagellum short, 7-jointed. Accessory flagellum 5-jointed. 

 Second antennae with 4th joint slightly expanded below. Flagellum 

 8-jointed. Posterior lateral angle of third abdominal segment quadrate. 

 No dorsal prominences. First gnathopod simple, dactyl small and weak. 

 Fourth, fifth and sixth joints provided on their under sides with brushes 

 of fine setae. Second gnathopod long and very slender. Fourth joint 

 provided below with fine setae. Fifth and sixth joints densely covered 

 with fine setae. Dactyl very small and weak. First and second peraeopods 

 with fourth joint expanded and having the lower anterior angle produced 

 downward. At the lower end of the sixth joint of the first two peraeopods 

 is a small backward pointing scale which is about half the length of the 

 dactyl. Third, fourth, and fifth peraeopods have the second joint ex- 

 panded into a broad backward and downward projecting lobe. The 

 fourth joint of these three peraeopods is greatly expanded into a back- 

 ward projecting lobe, the lower posterior angle of which dips down nearly 



31— Proc. Biol. Soc. Wash.. Vol. XXIX, 1916. (157) 



