﻿130 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 102 



Second antenna. — Shorter than body. Peduncle with squama clearly 

 visible. Flagellum shorter than peduncle, composed of about 14 

 articles. 



Maxilliped. — ^With three coupling hooks. 



First maxilla. — Outer lobe with 12 apical setae, inner lobe with 4 

 apical setae. 



Second maxilla. — Each of the 2 inner lobe lappets with 4 apical setae, 

 outer lobe with 10 setae. 



Mandible. — ^Lef t mandible incisor with five teeth, lacinia with four 

 teeth, setal row with four setae. Eight mandible lacking lacinia, in- 

 cisor with four teeth, setal row with five setae, the first two of which 

 are apically expanded with numerous teeth on cutting edge. Molar 

 process apically expanded. 



Adult male gnathopod. — Propodal inferior margin smooth, beset 

 with six small setae; carpal cutting edge with two teeth and a few 

 setae. 



Suhadult m^ale gnathopod. — Similar to female, having two pectinate 

 scales near inferior margins of carpus and propodus. 



Seventh peraeopod. — Nine 2-pointed setae on inferior margin and 

 three similar setae on superior margin of propodus of small specimen. 

 Other peraeopods similar in general to seventh. 



Vropod. — Posteromedial apex of ventral uropodal branch with a 

 distinct spinelike projection. 



First male pleopods. — Tips laterally expanded. Posterior margins 

 of each with six marginal setae in mature specimens. 



Female operculum. — Apex setiferous, evenly rounded, and with a 

 slight median emargination. 



Types. — ^Holotype, allotype, and 35 paratypes (13 females, 4 males, 

 and 18 juveniles) collected at the type locality, Dillon Beach, First 

 Sled Road, Marin County, Calif., in Mytilus biotope, January 23, 

 1948, bj^ R. J. Menzies. Type specimens have been deposited in the 

 collections of the following institutions: 



United States National Museum, holotype (No. 89530), allotype, 

 and 6 paratypes; Allan Hancock Foundation, 4 female paratypes; 

 Rijksmuseum Van Natuurlijke Historic, Leiden, Holland, 1 para- 

 type; Pacific Marine Station, 25 paratypes, accession numbers 1299- 

 1302 Arth. 



Geographical distribution. — Marin County, Calif. 



Material examined. — In addition to the type specimens the follow- 

 ing from California localities were examined : 



Marin County: Dillon Beach., from holdfast of alga Postelsia 

 palmaeformis washed onto beach, October 10, 1947, R. J. Menzies 

 collector, two juvenile specimens ; type locality, August 18, 1947, R. J. 

 Menzies collector, 1 juvenile ; Tomales Point, Tomales Bluff, May 23, 

 1948, 1 ovigerous female. 



