238 Di-. W. T. Caiman on 



setas on outer edge. Exopodite witli tliree slender apical 

 spines and some setge on outer edge (fig. 4). 



Adult male. — Total length y-4 mm. 



Carapace less inflated than in female, more than twice as 

 long as deep and one and two thirds as long as broad. 

 Pseudorostrum not more than one seventh of length of 

 carapace. The ridges and depressions described above in 

 the female are all present and there is a slight vertical ridge 

 on the anterior part of the side of the carapace. The surface 

 of the carapace is nearly smooth. 



Abdomen a little longer than cephalothoracic region. 

 Telson 1^ times as long as last somite, strongly gibbous 

 dorsally, with nine pairs of lateral spines. 



Antennular peduncle (fig. 5) stouter than in female, third 

 segment nearly. as stout and less than half as long as the 

 preceding, bearing distally a brush of sensory filaments. Outer 

 flagellum of five segments, the basal one dilated. Inner 

 flagellum (fig. 5 a) of three segments, the last very minute 

 and the first having a pair of stout spines at its distal end. 



Antennae as long as the body, of normal structure. 



Structure and proportions of third maxillipeds and legs 

 much as in female. All the legs except the last pair bear 

 exopods and have the basal segment expanded. 



Peduncle of uropods about one and four fifths as long as 

 telson, with numerous spines on its inner edge. Exopod 

 slightly longer than endopod and about two fifths of length 

 of peduncle. Endopod with seven spines on inner edge of 

 first segment, six on second, and three on third. 



First and second pairs of pleopods well developed, bi- 

 ramous ; exopod of two segments and endopod unsegraented. 



Remarks. — In the possession of vestigial exopodites on the 

 second and third legs of the female this species agrees with 

 those commonly referred to Leptostylis, and I accordingly 

 place it provisionally in that genus. It must be admitted, 

 liowever, that this character is open to suspicion as a generic 

 distinction in view of its variability, as described by Bonnier 

 in his Diastylopsis (?) dubia. In other respects the new 

 species differs considerably from L. longimana, the type of 

 the genus Leptosfi/Iis, notably in having the telson of mode- 

 rate size, with more than one pair of lateral spines. I have 

 elsewhere described a species (L. walkeri, Bull. Mus. d'Hist. 

 Nat. Paris, 1907, p. 121) having numerous lateral spines on 

 the telson, which is nevertheless closely allied to certain 

 undoubted species of Leptostylis, and the same character is 

 found in several species which Zimmer has referred to that 

 irenus. 



