10 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.64. 



minal joint has a row of seven sfJines around its margin, but no 

 hairs or setae. The basal joint of the endopod is unarmed, while 

 the terminal joint has a single spine and a fringe of short hairs. The 

 basal joints of the other legs have a fringe of hairs along their outer 

 margin, and the rami are armed with both hairs and spines but no 

 setae. 



Color, — (Preserved material) a uniform yellowish white without 

 pigment anywhere. But the specimeiw vvere evidently preserved in 

 picric acid so that their present color counts for very little. 



Total length 13 mm. Carapace 3.85 mm. long, 6.40 mm. across 

 its posterior margin. Genital segment 4.20 mm. long, 3.60 mm. 

 wide. Egg strings 15 to 20 mm. long and very slender. 



{nodosus^ covered with knobs, alluding to the sides of the fourth 

 segment and the anterior corners of the genital segment in the 

 male.) 



Specific characters of male. — Carapace orbicular, as wide as long ; 

 posterior lobes one-third the length of the carapace and broadly 

 rounded; posterior margin straight and unarmed; lateral grooves 

 distinct and S-shaped. First free segment with a lateral lobe on 

 either side extending diagonally backward; second free segment 

 transversely elliptical, one-half wider than long. Third free seg- 

 ment with each lateral margin j)rolonged into a conical knob, point- 

 ing diagonally forward and with a bluntly rounded tip; the seg- 

 ment in front of the knobs is narrowed into a short neck. 



The genital segment is oblong, nearly a half longer than wide; 

 the anterior corners are prolonged into knobs similar to those on 

 the sides of the fourth segment, while the posterior corners extend 

 backward in wide, bluntly rounded lobes, which are curved slightly 

 inw^ard. On the sides of the segment just in front of the posterior 

 lobes the rudimentary fifth legs are visible in ventral view. 



The abdomen is two- jointed and shaped somewhat like an hour 

 glass, being narrower across the groove that separates the two 

 joints, and wider across the anterior and posterior ends. The anal 

 laminae are huge affairs, each of them wider and longer than the 

 entire abdomen, overlapping at the center and tipped with four 

 large nonplumose setae. 



Of the appendages the second antennae are smaller than those 

 of the female but still larger than the average for these Nogaus 

 forms. The maxillipeds have a triangular basal joint but their 

 attachment is near the center of one of the sides instead of at one 

 of the apices. The terminal claw, instead of shutting down into 

 a pocket, shuts against two corrugated knobs on the basal joint. 

 The swimming legs are armed with stout plumose setae and spines 

 arranged as follows, the setae appearing first; first endopod, — 0, 

 4r— 0; first exoTDod, 0—1, 3—4; second endopod, 1—0, 8—0; second 



