62 BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



Female. — Head without a crest; body considerably shorter and 

 stouter than in the preceding species; genital segment armed on 

 the right dorsolateral surface with a strong curved spine, on the 

 left lateral surface at the posterior margin with two vertical rows 

 of 4 to 10 teeth; exopod of second antenna about twice as long as 

 endopod. Total length, 3.2-4.5 mm. 



Male. — Head without a crest; urosome at least one-third as long 

 as metasome; anal segment scarcely visible dorsally; enclopods of 

 fifth legs 1-segmented, exojjods 3-segmented; right endopod reaching 

 beyond the distal end of the middle' segment of the exopod ; the latter 

 fully as long as the end segment. Total length, 3-3.9 mm. 



Reranrks. — This species may be identified by the absence of a crest 

 and the presence of a curved spine on the dorsal surface of the 

 genital segment in the female, and by the pattern of the fifth legs 

 in the male. If A. Scott is correct in identifying the male of this 

 species with Lubbock's U7idina plumosa, then Lubbock's specific 

 name would take the place of that given by Giesbrecht. This is 

 difficult to decide, because Lubbock's description and figures are very 

 imperfect, and so it seems best to retain the name minor for the 

 present. Of this copepod Bigelow said : " So seldom entering the 

 Gulf of Maine, its chief local interest is as flotsam from the Atlantic 

 offshore." 



Family EUCHAETIDAE 



Genus EUCHAETA Philippi, 1843 



Body slender with the head narrowed anteriorly and the rostrum 

 more or less oblique; posterior corners of fifth segment covered 

 below with dense tufts of hair; genital protuberance on ventral 

 surface of genital segment very prominent in female; endopods of 

 first and second legs 1-segmented, of third and fourth legs 3-seg- 

 mented; exopods of first legs 2-segmented, of the three following 

 pairs 3-segmented; fifth legs lacking in female; right fifth leg of 

 male biramose, left uniramose. 



KEY TO THE SPECIES (BOTH SEXES) 



1. First antennae reaching beyond tips of caudal rami ; genital 

 segment symmetrical ; 1 caudal seta on each side elongated. 



spinosa (p. 62) 

 First antennae not reaching beyond first abdominal segment; 

 genital segment asymmetrical ; none of caudal setae elon- 

 gated marina (p. 63) 



EUCHAETA SPINOSA Giesbrecht 



Figure 41 



Euchaeta spinosa Giesbrecht, Fauna und Flora des Golfes von Neapel, vol. 19, 

 p. 410, pis. 16, 37, 1892.— Sharpe, Proc. U. S. Nat. Mus., vol. 38, p. 410, fig. 

 1, 1910. 



