NEW MARINE ISOPODS — MENZIES 143 



Types.— Uolotype (U.S.N.M. No. 87412), allotype (U.S.N.M. No. 

 87413), and 1 male paratype (U.S.N.M. No. 87414) collected at type 

 locality, 3 miles west of mouth of Kussian River, Sonoma Comity, 

 Calif., July 13, 1947, by R. J. Waidzunas and Paul B. Quyle; found in 

 fine mud with the sea-star Luidia foliolata Grube and an apparently 

 new species of marine isopod belonging to the genus laniropsis. 



Geographical distribution. — Known only from the type locality. 



Remarks. — This species appears to be most closely related to Pleu- 

 rogonium albidum Beddard. It differs from that species in having 

 its pleotelson widely ovate and the length of the first peraeon somite 

 more than twice the length of the second peraeon somite. In P. al- 

 hidum the pleotelson is narrow and the first peraeon somite is con- 

 siderably shorter than the second peraeon somite. 



Subgroup Antiasini* Nordenstam, 1933 



Genus AMTIAS Richardson 



ANTIAS HIRSUTUS, new species 



FiGUEES 27, 28 



Holotype. — Male, length 1.2 mm, width at widest part of second 

 peraeon somite 0.6 mm. 



Allotype. — ^Length 1.5 mm., width 0.7 mm. 



Diagnosis. — Eyes on short stalks. Frontal margin bifurcating. 

 Preocular lobes large but not curved outward. First antenna 

 flagellum with three segments, last segment with a single sensory fila- 

 ment and a few setae at apex. Peraeon somites 1 to 4 with lateral 

 borders straight or very slightly convex. Epimeral plates visible in 

 dorsal view on somites 5 to 7 only. Mandibular palp not observed, 

 apparently lacking. Body covered with many large setae. Uropods 

 with short straight branches, peduncle slightly longer than branches 

 and is widest at distal end. 



Character of tody. — Dorsal and lateral surfaces of body covered 

 with many large setae. Cephalon and fourth peraeon somite with 

 numerous black chromatophores ; mediolateral areas of first to third 

 peraeon somites with a longitudinal line of black chromatophores; 

 remainder of animal cream colored. 



Cephalon. — Wider than long, eyes small and on short stalks at 

 posterolateral angles of cephalon. Preorbital lobe distinct, separated 

 from eye by a deep lateral depression. Frontal margin emarginate, 

 lateral lobes fringed with setae. 



Peraeon. — Anterior border of first somite slightly concave. So- 

 mites one to four with lateral borders straight or slightly convex, all 

 borders fringed with long setae. Lateral borders of somites 6 and 7 



• Considered by Nordenstam, p. 200, to be a subgroup of Hansen's Munnlni. 



