200 BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



task, apparently jointed a little beyond its center, is attached to the 

 fourth segment and extends far beyond the tip of the antenna. 

 Endopod of second antenna 3-segmented, the three segments about 

 equal in length, exopod 2-segmented and attached to the side of the 

 basal endopod segment, its distal segment three times the length of 

 the proximal. Mandibles peculiar, the masticatory blade armed out- 

 wardly with eight large curved teeth and inwardly with a long series 

 of minute saw teeth, projecting in a broad lobe beyond the inner 

 margin of the blade, the lobe tipped with a stout spine. Palp bira- 

 mose, the exopod with two apical setae shorter than the endopod 

 with four apical and one inner setae. 



First maxilla and its palp each tipped with a tuft of stout spine- 

 like setae; epipodal lobe lacking; second maxilla without any trace 

 of the single lateral lobe found in Tisbe^ the process on the inner 

 margin of the second segment near the center spatulate and fringed 

 with short hairs ; the outer margin also bears a small hooked process 

 beyond its center. In the maxilliped the third segment is distinctly 

 separated, and the terminal claw is very slender and much longer 

 than the second and third segments combined ; the accessory spine is 

 on the inside close to the base of the claw, and very short ; the basal 

 segment is fringed with short hairs on both lateral margins; the 

 second segment has a similar fringe on the inner margin, with five 

 hairlike setae at the proximal end and a single one near the distal 

 end. 



The segments of the rami of the swimming legs are all much 

 widened and laminated; their plumose setae are very long and are 

 jointed somewhere between the base and the center, the portion 

 proximal to the joint being often wider than the terminal portion. 

 The second, third, and fourth legs bear considerable resemblance to 

 those of Tisbe^ but the first pair are very different; the two basal 

 exopod segments carry a smooth acuminate outer spine, the end 

 segment has four apical setae, a short seta on the outer margin, and a 

 very long one on the inner margin, and no spines; all the setae are 

 jointed. The endopod is 2-segmented, and shorter than the exopod, 

 its segments nearly as wide as long, the basal one armed with a very 

 stout inner seta, not jointed, the end segment with four slender 

 setae, all jointed. The basal segment of the fifth leg is only slightly 

 expanded inside and armed there with one long seta and two very 

 short ones; the distal segment is almost linear and expanded at the 

 tip, where it carries five setae, the second inner one much shorter than 

 the others. Total length, 1.1-1.2 mm. Greatest width, 0.35 mm. 



Male. — Body similar to that of the female, but smaller and more 

 slender; urosome less than half the length of the metasome, the 



