122 BULI^TIN 15 8, UNITED STATES NATIONAL MUSEUM 



METRIDIA PRINCEPS Giesbrecht 



Figure 81 



Metridia princeps Giesbrecht, Atti Accad. Lincei, Rome, ser. 4, vol. 5, sem 

 2, p. 24, 1889; Fauna und Flora des Golfes von Neapel vol 19 n S4o' 

 pi. 33, 1892. • . y- ow, 



Occurrence.— One female and three males from the trawl wings 

 Stations 2093, 2173, 2219, 2229, Albatross, south of Marthas Vine- 

 yard. 



Distribution.—Southern Atlantic (Thompson); tropical Pacific 

 (Giesbrecht); California coast (Esterly) ; South African seas 



(Cleve,Stebbing) ; Gulf of Maine 

 (Bigelow). 



Color. — Body translucent, with 

 a bright-red line through the cen- 

 ter of the abdomen and the pos- 

 terior portion of the thorax and 

 a large spot of the same color at 

 the bases of the mouth parts ; no 

 eye spot visible (Rathbun). 



Femule. —Metsisome elliptical, 

 considerably narrowed anteri- 

 orly; urosome two-thirds as long 

 as metasome; genital segment 

 longer than abdomen; caudal 

 rami five times as long as wide; 

 first antennae reaching beyond 

 tips of the caudal rami ; fifth legs 

 4-segmented, basal segment with 

 a tuft of long hairs on the an- 

 terior surface, second segment 

 with a stout plumose seta at the 

 outer distal corner, end segment 

 with three apical setae, about 

 equal in length and plumose only 

 proximally. Total length, 8-8.5 

 mm. 

 Male.— Vrosome four-fifths as long as metasome, anal segment 

 extending backward on each corner in a short blunt process, outside 

 the caudal ramus; the latter more than six times as long as wide; 

 right fifth leg 5-segmented, the second segment with an outer seta' 

 the spiniform process on the inner margin of the third segment 

 smooth, the end segment considerably swollen and longer than the 

 two preceding segments combined; left fifth leg 3-segmented, basal 

 segment with a tuft of long hairs, second segment fringed with 

 short hairs on the inner margin, end segment longer than the other 



FiGDRE 81. — Metridia princeps: a, Male, 

 dorsal ; 5, female, fifth legs ; c, male 

 fifth less 



