346 



BULLETIIT 15 8, UNITED STATES NATIONAL MUSEUM 



Figure 2 6 . — Hemicyclops 

 adherens: a. Female, dor- 

 sal (after Williams) ; b, 

 female, fifth leg 



First antennae shorter than the cephalic segment; second antennae 

 tipped with seven elongate, curved unequal setae ; middle segment of 



maxillipeds not produced on the inner mar- 

 gin and without setae. Endopods of swim- 

 ming legs longer than exopods; distal 

 segment of fifth legs elliptical, more than 

 twice as long as wide, with four marginal 

 setae, the second inner one filiform. Total 

 length, 1.2-1.3 mm. 

 Male. — Unknown. 



Remarks. — Williams placed this species in 

 the genus Lichomolgibs, but several characters 

 render such an assignment impossible. The 

 structure of the second antennae, the mouth 

 parts, the endopod of the fourth legs, and the 

 fifth legs are all very different from those of 

 the genus Lichomolgus and agree quite 

 closely with those of the genus Hemicyclops.^ 

 the differences being such as would be expected in a new species of 

 that genus. Accordingly the species is here transferred to Hemicy- 

 clops. 



Family LICHOMOLGIDAE 

 Genus MYICOLA Wright, 1885 



Metasome of female cylindrical, of male flattened and elliptical; 

 fifth segment rather abruptly narrowed; urosome 4-segmented in 

 female, 5-segmented in male; genital segment short with convex 

 sides; caudal rami long and narrow. First antennae 6- or 7-seg- 

 mented; second antennae 3-segmented, prehensile; maxillipeds lack- 

 ing in the female, present and well developed in the male. Rami of 

 first four pairs of legs 3-segmented; fifth legs uniramose, 2- or 3- 

 segmented. 



KEY TO THE SPECIES (BOTH 8EKE8) 



1. Second antenna with a single apical claw; fifth leg 3-seg- 

 mented mitisiensis (p. 346) 



Second antenna with 2 claws and 3 setae ; fifth leg 2-segmented_ 

 major (p. 347) 



MYICOLA METISIENSIS R. R. Wrigrht 

 FlQUKE 207 



Myicola metisiensis Wright, Amer. Nat., vol. 19, p. 118, pi. 3, figs. 1-10, 1885. 



Occurrence. — Found in the mantle cavity of the long-necked clam 

 {Mya arenaria)., at Wellfleet, Mass., 1925. 



Distribution. — In mantle cavity of same host at Little Metis, 

 Quebec (Wright). 



