128 SPOLIA ZEYLANICA. 
The head of the male is produced in front, beneath the frontal 
process, into a distinct, downwardly-curved, spiniform rostrum 
(fig. 4). The segments of the thorax are simple, as are also those 
of the abdomen in the female. In the male, on the other hand, 
each segment, with the exception of the first and the last, bears one 
or more spines. The second segment bears only a lateral pair, but 
the next five bear both a pair of long dorsal spines and a lateral 
spine on each side diminishing in size in the posterior segment. 
The seventh segment bears a pair of dorsal spines and a pair of very 
minute lateral spines, and the eighth a single median dorsal spine. 
The caudal rami in both sexes are long. In the male they are only 
slightly curved, ciliated at their base, but provided for about the 
distal two-thirds of their length with strong curved spines on either 
side (fig. 8). In the female they are more divergent, and fringed 
with setz along both edges. 
Unlike the majority of the genus Streptocephalus, the male has 
the frontal processes enormously developed. They ‘are fused at 
their base into a single cylindrical process, but are distinct for the 
greater part of their length. Distally they divide again into dorsal 
and ventral branches. The ventral branch is short and simple, 
but the dorsal branch bears a row of papille along its ventral edge. 
The first pair of antenne are long, in the male about equalling in 
length the first joint of the second antenne, and in the female 
somewhat exceeding the length of the second pair. The second pair 
of antenne in the female are short, narrow, triangular plates fringed 
with hairs, but without any terminal projection. Those of the male 
are long chelate appendages. The basal segment is about equal in 
length to the second segment and bears a long apophysis: the 
terminal portion is narrow and produced into two long sub-equal 
processes. Each of these has a small inner lobe at its base of some- 
what variable form (fig. 5). The branchial legs are of the usual 
form (figs. 6 and 7). The basal plate (bract) has its edge serrated. 
The exopodite is much longer than the endopodite, the distal margin 
of the latter more or less squarely truncated. The penis of the male 
(fig. 9) scarcely extends beyond the third abdominal segment, the 
reversible part not spinous. The egg-sac of the female is narrow, 
cylindrical, and pointed at the extremity, reaching to the middle 
of the sixth segment of the abdomen. 
Three males and three females of this species were collected by 
Mr. Green, who describes its appearance in life as follows : —“‘ Pro- 
minent black eyes; body pale translucent, yellowish-greenish ; 
a pair of brilliant scarlet cerci at extremity.”” One or two of the 
specimens have what appear to be large branching chromatophores 
