342 PROCEEDINGS OF THE NATIONAL MUSEUM vol. i08 



Pleotelson: Composed of a single somite, with lateral incisions 

 partially separating a second somite at the base. Greatest width 

 between the posterolateral angles about three-fourths the length. 

 Posterior end terminating in a rounded apex, with concave lateral 

 margins. Central portion of dorsum elevated into a ridge decreasing 

 in height posteriorly. In the male tlii-ee slight but distinct tubercles 

 are present on this ridge at the base; only the faintest indications of 

 these tubercles are found in the female. Uropod with triangular 

 apical segment, peduncle grooved along free lateral margin and 

 bearing a single plumose seta at distomedial angle. 



Appendages: Antenna 1: Composed of four short segments, not 

 five as stated by Boone; first segment very plump, slightly shorter 

 than second and third combined; flagellum bearing a group of fda- 

 mentous setae at the distal end. 



Antenna 2: Slightly longer than half the length of the body. 

 Peduncle composed of five segments, distal ends of segments 2-4 flaring 

 widely. Flagellum about as long as peduncle segment 4, bearing 

 distally a number of filamentous setae. 



Mandible: Molar process with edges divided into a few blunt 

 teeth; setal mass formed of densely clumped setae, some very long. 

 Incisor with five teeth; lacinia mobilis with three teeth. Setal row 

 formed of six spinulate setae. 



Maxilla 1: Outer lobe bearing 13 stout setae and a single slender 

 plumose seta at the apex. 



Maxilla 2: Composed of two lappets; outer lappet bilobed, bearing 

 seven and sLx comblike setae on the outer and inner lobes respectively; 

 inner lappet with 10 setae at the apex. 



MaxiUiped: Palp of four segments; endognath with a single coupling 

 hook. 



Pereiopods: Dactyls biunguiculate. Pereiopod 1 bearing a single 

 row of about 10 comblike setae on medial surface of propodus near 

 posterior margin. Basipods of pereiopods 2-7 bearing two pau's of 

 bosses armed with short spines. 



Penis: Consists of two plates, concealed by the uropods. 



Color: After 38 years in alcohol, the male is without pigmentation 

 except in the eyes and in the previously mentioned areas of perion 

 somite 1, which Boone called "false eyes." The female is pigmented 

 more or less uniformly brownish black (in alcohol) over the entire 

 dorsal surface; no "false eyes" are evident. 



Localities: The holotvpe was collected by E. P. Chace on Oct. 17, 

 1917. at San Pedro, Calif., from near the foot of the breakwater. 

 The female was collected by R. J. Menzics on Aug. 2, 1942, at La 

 Jolla, Calif., from eel grass (Phyllospadix) . 



