NO. 4 SCHULTZ: ISOPODA 19 



Uropodal rami both with large plumose setae; endopod about as long as 

 telson. 



Measurements: Holotype male about 4.0 mm long. 



Type locality: 6805(1); Santa Cruz Canyon; 218 m; Dec. 22, 

 1959; rocks and some green sand. Lat. 33° 56' 03"N, Long. 119° 52' 

 03"W. 



Distribution: Known only from type locality. 



Affinities: The new species is very similar to Gnathia crenulati- 

 frons Menzies and Barnard (1959), except that it has an acutely 

 pointed projection from the anterior margin of the cephalon. The telson 

 of G. crenulatifrons is short, not as produced as the telson of G. 

 hirsute. 



Gnathia trilobata, n. sp. 



(Plate 13) 



Diagnosis: Large unstalked eyes. Head with trifid frontal projection 

 with stiff marginal setae. Peraeonal segment one conspicuous; complete 

 width visible in dorsal view. Front half of body covered with many 

 small tubercles, especially prominent on cephalon, anterior four per- 

 aeonal segments and postero-lateral border of segment six. Lateral ex- 

 tensions of pleonal segments increasingly more prominent posteriorly 

 in dorsal view; telson produced in acutely rounded apex. Pylopod with 

 three segments (third minute) with long plumose setae on margin and 

 larger plumose setae on ventral side. First walking peraeopod with plu- 

 mose setae on basis and at least one plumose seta on each segment except 

 dactylus; sensory setae present distally on merus near carpal-meral 

 joint. Both antennae about as long as cephalon; first with seven flagel- 

 lar articles; second with five articles. Maxilliped with many plumose 

 setae; blade with three coupling hooks, slightly longer than third seg- 

 ment. Mandible with several teeth and outer marginal notch; no setae 

 on mandible. Pleopods without setae. Uropod with many large plumose 

 setae arising from exopod and endopod; endopod and exopod shorter 

 than telson. 



Measurements: Holotype male 5.0 mm long. 



Type locality: 6851; Coronado Canyon; 812 m; Feb. 1, 1960; 

 green mud. Lat. 32° 30' 42"N, Long. 117° 21' 37"W. 



Materials examined: 6851 (2) ; 7049 ( 1 ) . 



Distribution: Known from Coronado Canyon (type locality) and 

 from La Jolla Canyon w^here it was taken from a polychaete tube in 

 green sand and mud at 976 m. 



