6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 9I 



minute segment instead of two at its apex, and the rudimentary palp 

 is made up of three fingerhke processes without setae. The second 

 maxilla (fig. 19) has a shorter second segment, and the terminal claw, 

 instead of being cylindrical and uniformly curved for its entire length 

 as in crypturus, is flattened and bent at right angles near the tip. In 

 the maxilliped the terminal claw has its basal three-fifths enlarged 

 into an elliptical pad from which projects the slightly curved distal 

 two-fifths, the tip of which fits into the cup. The basal pad carries 

 on its lateral surface a process terminating in a small curved accessory 

 claw (fig. 20). 



The arrangement of the spines and setae on the swimming legs is 

 as follows. First exopod i-o, 4-3; endopod 0-0, 0-3. Second exopod 

 i-i, 4-5 ; endopod o-i, 0-7. Third exopod i-i, 4-4; endopod o-i, 0-4. 

 Fourth exopod 5-0; endopod i-o. The fourth exopod is twice the 

 length of the endopod, and its five coarse spines are bunched around 

 its tip. The fifth legs are each replaced by two small spines on the 

 ventral surface of the posterior lobes of the genital segment and are 

 very difficult to discern. 



Total length of female 5-6 mm. Length of cephalothorax, includ- 

 ing the posterior lobes, 2.60 mm. Width of cephalothorax 2.90 mm. 

 Length of genital segment 3.10 mm; width of same 1.63 mm. 



The male. — Cephalothorax wider than long and more than half the 

 entire length including the posterior lobes. The frontal margin is 

 strongly curved and emarginate at the center ; the posterior lobes are 

 short and narrowly rounded. The second segment is longer than 

 either the third or fourth and without lateral lobes. The third and 

 fourth segments are transversely elliptical with strongly convex lateral 

 margins. The genital segment is as wide as the fourth segment and 

 one-fourth longer, with convex lateral margins and short posterior 

 lobes. The abdomen is one-segmented, very short on the lateral mar- 

 gins and twice as long on the midline, with the posterior corners ob- 

 liquely truncated. The caudal rami are circular, each a third as large 

 as the abdomen, with four curved setae of about the same length. 



The appendages are like those of the female, with a few modifica- 

 tions. The basal portion of the terminal claw of the second antenna 

 is relatively larger and the basal pad on the terminal claw of the 

 maxilliped is longer and wider (fig. 33). The arrangement of the 

 spines and setae on the first three pairs of legs is exactly the same as 

 in the female, but the setae are relatively much larger and their plumes 

 longer and denser. In the fourth legs the exopod has four spines and 

 four setae and the endopod has three terminal setae and one on the 



