650 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvm. 



with an emarginate posterior border and short, well-rounded lobes. 

 The abdomen is three-fifths the length of the genital segment, and like 

 the latter has a broad, barrel shape, abruptly narrowed into a neck, 

 where it joins the genital segment. 



The anal lamina? are large and foliaceous, separated more than their 

 own diameter, and armed with large and stout seta?. 



The egg tubes are about half as long as the body; each has a diameter 

 a little more than half that of the abdomen and contains 60 eggs. 

 The anterior antennae are of medium size and very heavily armed with 

 seta? and spines; the posterior pair have a stout basal joint and a long, 

 slender terminal hook. The accessory spines situated just posterior to 

 the base of these antenna? are small and weak. 



The first maxilla? are of medium size, slightly curved, and consider- 

 ably enlarged at the base; the second pair are large and stout, as long 

 as the proboscis, and abruptly curved near the base. 



The terminal portion is nearly straight and ends in a rather blunt 

 point. The terminal joint of the first maxillipeds is much longer than 

 the basal and is tipped with two long and curved claws, the inner of 

 which is longer than the outer, and has a serrate lamina along its 

 anterior and posterior margins. There is also a stout curved spine 

 upon the anterior margin of this terminal joint near its distal end. 



The second maxillipeds are large and stout, the terminal claw about 

 half the length of the swollen basal joint, with a long accessor}?- spine 

 upon its inner margin close to the tip. 



The inner margin of the basal joint is also raised into a slight 

 protuberance just opposite the point of the claw. 



The furca is narrow, the base as long as the branches and slightly 

 swollen; the branches are straight, almost parallel, and acute. The 

 three terminal claws on the first swimming leg are long and strongly 

 curved, decreasing in size from the anterior to the posterior. There 

 is no seta at the distal corner, but the three plumose seta? on the 

 posterior margin are of the usual size. The second legs are noticeable 

 chiefly for the spines on the exopod and the curious shape of its ter- 

 minal joint. There are but two spines, one on the basal joint and one 

 on the second joint; the former is about three times the length of the 

 latter, and stretches across the second joint and projects bej^ond its 

 inner border nearly a third of its length. The terminal joint of this 

 exopod is shaped like the quadrant of an ellipse, the half of the 

 shorter diameter joining the second joint, while the half of the longer 

 diameter forms the anterior border. The plumose seta? are arranged 

 in a row around the curved posterior margin. 



The rami of the third legs are well separated; the exopod has a stout 

 basal joint with a medium-sized claw, and a considerably smaller ter- 

 minal joint, both joints being appressed closely to the margin of the 

 apron. The fourth legs are long and slender, three-jointed with five 



