126 



BULLETIN" 15 8, UNITED STATES NATIONAL MUSEUM 



laminate, with two dense tufts of long hairs on its outer margin. 

 Total length, 3-3.35 mm. 



Remarks. — The teeth on the anterior margin of the basal segment 

 of the first antennae are the best single distinctive character. Esterly 

 found this species common in both summer and winter on the Cali- 

 fornia coast, but it seems to be only a straggler in the present area 

 from the open ocean. 



PLEUROMAMMA ROBUSTA (Dahl) 



Figure 84 



Pleuromma robustum Dahl, Zool. Anz., vol. 16, p. 105, 1893. 



Pleuromamma rodusta Saes, Crustacea of Norway, vol. 4, p. 115, pis. 78, 79, 1902. 



Occurrence. — Two females in surface tow south of Gay Head, 

 September, 1883; 25 males and females from trawl wings, Stations 



2173, 2195, 2236, Albatross, south 

 of Nantucket ; 12 males and females 

 in vertical haul. Station 10295, 

 Grampus. 



Distribution. — Atlantic (Dahl) ; 

 Norwegian coast (Sars) ; South 

 African coasts (Cleve, Stebbing) ; 

 Adriatic, Eed Sea, Indian Ocean 

 (Pesta) ; Faroe Channel, Irish 

 coast (Norman) ; Gulf of Maine 

 (Bigelow). 



Color. — Body fairly transparent, 

 with scattered flecks of red through 

 the head and thorax, and an elon- 

 gated spot on the ventral surface, 

 embracing the mouth, the mouth 

 parts, and the first two pairs of 

 legs, which is dark red ; eye spot a 

 dark ruby red. 



Female. — Body more robust than 

 in the other species; metasome 

 narrowed anteriorly; head separated from first segment; urosome 

 half as long as metasome; genital segment no longer than the first 

 abdominal segment and protruding ventrally; caudal rami shorter 

 than the anal segment; fifth legs 4-segmented, the second and third 

 segments with stout setae on the outer margin, the third and fourth 

 segments fringed with long hairs on the inner margin, the end seg- 

 ment tipped with three setae, the inner one longer than the entire leg. 

 Total length, 4-4.5 mm. 



Figure 84. — Pleuromamma robusta: a. 

 Female, dorsal (after Sars) ; 5, female, 

 fifth legs ; c. male, fifth legs 



