COPEPODS OF THE WOODS HOLE REGION 173 



anterior surface, the one on the basal segment almost in the center 

 of that surface, the one on the middle segment nearer the inner 

 margin. 



Family ECTINOSOMIDAE 



Genus ECTINOSOMA Boeck, 1864 



Body more or less spindle-shaped, the metasome scarcely wider 

 than the urosome; head fused with the first segment and tapered 

 anteriorly into a tongue-shaped rostral plate. Urosome 4-segmented 

 in female, apparently 5-segmented in male, owning to the subdi- 

 vision of the genital segment. In the female the genital segment is 

 without any traces of subdivision, the anal segment is much shorter 

 than those preceding it, and the caudal rami are short and some- 

 what divergent, the two apical setae close together and enlarged at 

 their bases. First antennae small, 5- to 7-segmented; exopod of 

 second antennae 3-segmented; first four pairs of legs with 3-seg- 

 mented rami; fifth legs 2-segmented, distal segment 3-lobed, each 

 lobe with a single seta, inner expansion of basal segment with two 

 setae. 



KEY TO THE SPECIES (BOTH SEXES) 



1. Accessory seta of distal segment of fifth legs on lateral margin of 



segment, close to outer terminal seta normani (p. 173) 



Accessory seta of distal segment of fifth legs on anterior surface 

 of segment near its base 2 



2. Outer seta of distal segment of fifth legs much longer than inner ; 



end setae of exopod of second antenna nearly equal__ elongatum (p. 175) 

 Inner seta of distal segment of fifth legs longer than outer ; end 

 setae of exopod of second antenna very unequal curticorne (p. 174) 



ECTINOSOMA NORMANI T. and A. Scott 

 FiGtIKB 118 



Ectinosoma notinani T. and A. Scott, Trans. Linn. Soc. London, ser. 2, vol. 6, 

 pt. 5, p. 435, pi. 36, figs. 21, 29, 1S96.— Saks, Crustacea of Norway, vol. 5, 

 p. 35, pi. 19, fig. 2, 1904. 



Occurrence. — Twenty-five males and females were obtained by 

 Rathbun in Little Harbor, Woods Hole, September 6, 1881. 



Dktrlhution.—F'wth. of Forth (T. Scott); Ceylon (A. Scott); 

 Vadso, Finmark (T. Scott) ; Norwegian coast (Sars) ; Adriatic 

 (Grandori, Pesta) ; Indian Ocean (Thompson and Scott) ; Chesa- 

 peake Bay (Wilson); Charlestown Pond, R. I. (Williams). 



Color. — Body a uniform light gray, with a pair of conspicuous 

 red patches on each side of the head between the bases of the two 

 pairs of antennae. 



Female. — Body spindle-shaped, with the greatest width in front 

 of the middle ; rostral plate short and blunt ; caudal rami as wide as 

 71937—32 13 



