32 DK. W. T. CALMAN ON NEW OK RAEE 



b. One pair o£ pleopods Id male Paraleucon, g. n. 



c. No pleopods in male Hemileucon, g. n. 



B. First two pairs of legs only carry exopods in both sexes. No pleopods 



in male Heteroleucon, g. n. 



LeUCON (■?) HETEROSTTLIS, sp. n. (Plate VIII. figs. 1-5.) 



Descrijition of adult Female. — Total length 3-42 mm. 



Carapace a little over one-fifth of total length, its vertical height less than two-thirds 

 of its length. The dorsal edge is nearly straight, coarsely and somewhat irregularly 

 serrated in the anterior half, with a small denticle near the posterior end and in front 

 of it a shallow depression. Pseudorostrum straight, horizontal, acute, measuring along 

 its upper edge about one-fourth of the total length of the carapace. The antennal 

 notch forms a deep rounded sinus in the antero-lateral margin, which, above the notch, 

 is cut into about four coarse teeth. On the antero-lateral corner begins a series of 

 strong acute teeth, diminishing to faint serrations on the lower margin. The side of 

 the carapace is smooth. The abdomen is longer than the cephalothoracic region and 

 stout, the first two somites being not longer than broad. 



The antennules have the first segment of the peduncle longer than the second, which 

 is again a little longer and stouter than the third. The outer flagellum is a little 

 longer than the last segment of the peduncle and is composed of three segments, the 

 first and second subequal and the third minute. The inner flagellum is unsegmented 

 and is nearly equal to the fii'st two segments of the outer flagellum together. The 

 antennae are composed of three segments, the basal one bearing three plumose setae. 

 The branchial apparatus has two small papilliform lobules on its posterior part. 

 The first legs are imperfect in all the specimens examined. 



The second legs have the ischium represented by two very narrow semiannular 

 sclerites interposed between the basis and merus, forming a ring which is interrupted 

 on the inner and outer sides. 



The uropods have the peduncle longer than the last somite and about three times 

 as long as broad. The rami are very unequal, the exopod being shorter than the 

 peduncle and little more thau half the length of the endopod. The latter is composed 

 of two segments, the proximal two and a half times as long as the distal. There are 

 about ten slender spines on the inner edge and two unequal spines at the tip, while 

 the outer edge bears a series of stout setae. The exopod bears a series of long setae 

 on the inner edge and at the tip and some short setae on the outer edge. 



Remarks. — In the absence of the male it is impossible to decide whether this species 

 ought to be referred to some of the new genera defined below. Its resemblance, 

 however, in such characters as the shape of the antero-lateral edge of the carapace, to 

 L. longirostris Sars leads me to believe that it will be found to belong to the genus 



