3 G 
J. M. Thomson. 
Urosome half as long as cephalothorax. Genital segment has rounded 
projections at about the middle of its length and widens again posteriorly. 
The projections bear a group of spinules, the posterior one of which is 
somewhat stouter than the rest. There is also a short spine on the posterior 
swelling. Ventrally on the genital segment, lateral to the genital aperture 
and immediately behind it, is a pair of short spines. At about the same 
distance apart and in front of the aperture occur another pair. On each 
side a row of minute spinules run inward and forward from the posterior 
pair. Second segment of urosome half as long as first; the third is longer 
and rectangular; the fourth is as long as the second. Caudal rami long and 
slender. They are divergent and ciliated along the whole length of the 
inner side, and in a cluster behind the lateral seta on the outer. The lateral 
seta is inserted two-thirds of the distance along the margin. The other 
four of equal length are inserted close together on the truncated end. 
Appendages : Antennule has twenty-five segments, some of the proxi- 
mal being very short. Second antenna biramous, rami subequal; exopod six- 
segmented with three terminal setae on the distal segment. Mandibles strong 
and expanded, with eight somewhat rounded denticles, the outermost the 
largest and separated from the rest by a sinus; a slender seta stands at the 
inner end. Maxillae and maxillules normal ; maxillipeds long and slender, 
the distal segments with dense setae; four borne on the second segment. 
The natatory appendages are slender, with 3-segmented rami, the en- 
dopods somewhat shorter than the exopods. The second segment of the first 
exopod is without an external spine. The external spines are weakly denti- 
culate. Distally each exopod bears a stouter denticulate spine and a seta. 
The fourth pair of appendages are asymmetrical in that the left bears a long- 
curved coxal spine extending* to the end of the middle segment of the cndo- 
pod. The right coxa has a short curved sparsely ciliate spine. Coxae of 
all other natatory limbs have a slender straight seta. The fifth pair have 
the second and third segments of the exopods equal in length; a long curved 
spine arises from the inner side of the middle segment and reaches to the 
end of the third segment. 
Ovisac rounded, and ventral in position. 
Male. 
Length 1-26 mm. Metasomc narrow compared with that of female. 
Urosome slender, five-segmented. Caudal rami of the same relative length 
as in the female but without external cilia below the outer seta, and with 
a fifth terminal seta, more slender and much shorter than the others, between 
and dorsal to the two innermost setae. 
Appendages: Left antennule as in female; the right modified, divided 
into three sections, the first of nine segments, some of which are very short, 
the last three with sensory setae; the second section contains five swollen 
segments and a long slender sixth, followed by the third section, which 
consists of two long curved segments which show signs of at least- four 
incipient segments which are not divided off. The other head apppendages 
including the maxillipeds are similar to those of the female. 
