618 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvm. 



21. Genital segment oblong, twice as long as wide; basal abdomen joint the wider, 



bntshorter monocantJms (Heller, 1865). 



22. Females, genital segment quadrate, nearly as long as carapace; no lobes. 



poUachii (B-Smith, 1896). 

 22. Females, genital segment bell-shaped, lialf the carapace; lobes long and 



broad e.rculpatus (Fischer, 1860). 



28. Females, genital segment elliptical, lolies short and broad; fifth legs concealed 



dorsall J' i<almo)ris ( Kroyer, 1838) , p. 640. 



28. Males, genital segment sjnndle-shaijed; lobes narrow and two-thirds as long as 



abdomen .flores (van Beneden, 1892). 



i'S. Males, genital segment broad acorn-shaped; no lobes; both fifth ajid sixth legs 

 visible inferoirreiis (Kroyer, 1863). 



LEPEOPHTHEIRUS LONGIPES, new species. 

 Plate XVIII, figs. 206-211, 222. 



Fertiale. — Carapace elliptical, one-seventh longer than wide. Frontal 

 plates well ronnded and deeply incised at the center. Posterior sinuses 

 of medium width, with the sides nearly parallel; median lobe rather 

 more than half the entire width and projecting well l)ack of the lateral 

 lobes. Free thorax segment f our-tifths as wide as the genital segment, 

 four times as wide as long. 



Genital segment oblong, somewhat less than half the width of the 

 carapace, a little wider posteriorly where it is produced into a narrow 

 conical lolje on either side. 



Abdomen narrow, oblong, two-jointed, the Imsal joint somewhat 

 the larger. Anal lamina^ long, narrow, and curved inward so much 

 at the tips that the two overlap. Egg strings about the same diameter 

 as the abdomen and three-fourths as long as the body. 



Anterior antenna? two-thirds the length of the frontal plates, well- 

 armed with set}^; posterior antennt^? slciider, the terminal claw niuch 

 longer than the basal joint and curved nearly a third of its length. 

 Both pairs of maxillw very slender, the first pair not much ciu'ved, 

 the second pair divided aljout to the center witli the branches close 

 together, parallel, and both curved slightly away from the rostrum. 

 Furca narrow and al)ruptly constricted at the btise; the branches very 

 thick and stout, divergent, and much longer than the base. 



Second maxillipeds stout, the claw three-quarters the length of the 

 swollen basal joint with an accessory spine longer and stouter than 

 ordinary. The plumose setie on the first swimming legs are short and 

 weak; the two outer terminal claws are pectinate, while the inner one 

 is smooth. On the second legs the spine at the tip of the basal joint 

 of the exopod is very large, nearly as long as the joint itself, and the 

 spines on the other two joints are also large. There is a curved claw 

 at the tip of the second joint of the endopod of these legs which is 

 totall}^ unlike anything observed in other species. The fourth legs 

 are very large, relatively much longer than in any other species. The 



