;514 PROCEEDINGS OF THE NATIONAL MUSEUM vol.99 



Second pair of muxillae. — Composed of two lappets. Outer lappet 

 bilobed, outer lobe with six slender setae, inner lobe with four slender 

 setae. Inner lappet with 2 lobes, outer lobe with 3 slender apical setae 

 and 5 stout denticulate setae, inner lobe with 11 slender setae. 



Mandible. — Molar process tubular with truncate cutting end having 

 three setae. Palp three- jointed, first two joints subequal in length, 

 third joint about one-third the length of second joint and bearing two 

 elongate spinulate setae at apex. Incisor with toothless knifelike edge. 

 Left mandible with a four-toothed lacina and about five setae in setal 

 row. Eight mandible lacking lacina but with a lacinoid seta followed 

 by three setae in setal row. 



Gnuthopod. — Composed of enlarged and twisted segments. Tips 

 of fingers black. Cutting edge of movable finger with about five teeth 

 (not counting tip of finger as a tooth) in females and young males, 

 adult males with a single large tooth. Cutting edge of immovable 

 finger having about ten subequal teeth in females and young males. 

 In adult males fewer but more enlarged teeth are present. Left and 

 right gnathopods not differing conspicuously in size from one another. 



Second peraeopod. — Basis with large spinelike tubercles on supe- 

 rior margin. Ischium set in distal articular margin of basis and 

 scarcely discernible. Merus with thick spine at superior and inferior 

 distal angles, carpus with one thick spine at distal superior and infe- 

 rior angles, propodus with single thick spine on superior distal angle 

 and four similar spines on inferior border. Dactylus having a single 

 black-tipped claw. Inner distal angles of merus, carpus, and propo- 

 dus with spinulate setae. 



Seventh peraeopod. — Setae much reduced in number. Merus and 

 carpus with a thick seta on distal superior angle. Propodus with two 

 strong setae on inferior margin. Ischium proportionally consider- 

 ably longer than ischium of second peraeopod. Dactylus more strongly 

 developed than on second peraeopod, tip black. 



Type locality. — Tomales Bluff, Marin County, Calif., south of reef 

 on holdfasts of the alga Laminaria sp. and under stones in the lami- 

 narian zone of open rocky coast. May 23, 1948. 



Material examined. — Specimens were examined that had been col- 

 lected from the following localities in northern California : 



Marin County : Rocks north of Pacific Marine Station.^ August 18, 

 1947, R. J. Menzies, 1 ovigerous female ; March 22, 1948, R. J. Menzies, 

 3 males, 3 females, 1 juvenile; May 12, 1948, R. J. Menzies, 1 female; 

 May 15, 1948, Margaret Barr, 8 females, 3 ovigerous, 2 juveniles; 

 Tomales Bluffs hay side, November 28, 1947, R. J. Menzies, 1 male; 

 May 23, 1948, R. J. Menzies, 2 males, 3 females ; Tomales Point, ocean 

 side, August 18, 1947, R. J. Menzies, 1 female, May 23, 1948, 3 males, 

 3 females; Tomales Point, reef, November 30, 1947, R. J. Menzies, 

 1 male young; May 23, 1948, R. J. Menzies, 11 males, 19 females, some 



