248 BULLrETIN 15 8, UlSriTED STATES NATIONAL MUSEUM 



long as the whole antenna; exopod of second antenna 2-segmented, 

 distal segment very short; end segment of first endopod twice as 

 long as middle segment, the two combined half the length of the 

 basal segment ; rami of three following pairs of legs with long apical 

 setae; basal expansion of fifth legs obtusely rounded, reaching the 

 middle of the distal segment, with four setae, the second outer one 

 the longest; distal segment oval, twice as long as wide, with five 

 very unequal setae, the second inner one filiform and much elon- 

 gated. Total length, 0.6-0.7 mm. 



Male. — Smaller than the female, seven times as long as wide ; first 

 antennae stouter and not so long, 8-segmented, the aesthetask longer 

 than the entire antenna. In the first legs the end segment of the 

 endopod is twice as long as the middle segment, but the two com- 

 bined are as long as the basal segment; the middle segment of the 

 first exopod is without a seta. The basal expansion of the fifth legs 

 does not reach the center of the distal segment and is armed with 

 two very unequal setae ; the distal segment is somewhat quadrangu- 

 lar, with three apical setae and one on the outer margin at the center, 

 all four short. Total length, 0.45-0.55 mm. 



Reinarks. — This is the first record of the species outside of Scot- 

 land and Norway. It may be recognized by its slender form and 

 the exceptionally long caudal setae, as well as by the first and fifth 

 legs. It is worthy of note that both Scott and Sars obtained their 

 specimens from submarine banks of sand, but at considerable depths. 

 From the location of the present specimens it is evident that Ihey 

 also come into shallow water near shore. 



PARALEPTASTACUS, new genus 



Body slender and cylindrical, about the same diameter throughout, 

 without definite demarcation between metasome and urosome; head 

 fused with the first segment, rostrum well defined; urosome 4-seg- 

 mented in female, 5-segmented in male ; caudal rami short and armed 

 with stout spines. First antennae 7-segmented, the second segment 

 the longest, twice geniculate in male, at the distal ends of the second 

 and fourth segments; second antennae with a minute 1-segmented 

 exopod, attached to the side of the proximal endopod segment near 

 its base, with indications of a jointing of the endopod segment at 

 the point of attachment; maxilliped unguiculate, the terminal claw 

 very long and slender. Exopods of the first four pairs of legs 

 3-segmented, endopods 2-segmented, tipped with a single long seta; 

 fifth legs 2-segmented, the inner expansion of the basal segment 

 with two setae. 



Genotype. — Paraleptastacus trevicaudatus, new species. 



Remnarhs. — This new genus resembles Leptastacus in the peculiar 

 and strong development of the maxillipeds and in the general char- 



