1912.] R. B. SEYMOUR-SEWEI,L: Surfjace-Living Copepoda. 347 
There are three groups of small triangular spines on the 
posterior surface of the proximal joints, and with the exception of 
the distal three segments, all the others bear transverse rows of 
spines posteriorly. 
The 2nd antenna is of a somewhat unusual type. The basal 
portion consists of the usual two segments; the Ist basal bears a 
single and the 2nd basal two setae, and the margins are fringed 
with hair. The endopodite appears to be fused with the second 
basal joint and bears a crown of seven setae. The exopodite con- 
sists of a single joint and bears 9 setae. 
The mandible is furnished with four teeth, of which the Ist 
is separated from the remainder by a wide interval. 
The 2nd maxilla resembles that of other members of the 
genus, 
The maxilliped presents a resemblance to that of other mem- 
bers of the genus Acartia; the 3rd joint bears four sharp spinous 
processes and the 2nd joint carries a row of 4 triangular teeth on 
the margin. 
The ist pair of legs. The exopodite consists of three segments. 
There is no marginal spine on exopod 2; both exopod 1 and 2 
catry a single seta on their inner margins and exopod 3 has a row 
of five. The terminal spine is long and slender and is not serrated 
for some distance along the shaft ; the proportional lengths of the 
spine and the terminal segment are as 46: 16. The endopodite 
has two joints, of which the proximal bears a pair and the distal 
Six setae. 
The 2nd—ath pairs of legs. Each consists of a 3-jointed exopod 
and 2-jointed endopod. Each joint of the exopod bears a single 
marginal spine, and the end saw is very long and slender resem 
bling that of the Ist leg. The rst joint of the endopod bears 3 and 
the 2nd 6 setae. 
The 5th pair of legs is symmetrical and possesses a basal 
portion carrying a marginal bristle and a single-jointed exopodite 
and endopodite, of which the former is about twice the length of 
the latter and each is serrated. 
¢” Total length 1°45 mm. ; 
The cephalo-thorax resembles that of the female. The abdo- 
men is composed of four segments. 
The vight antenna is modified to form a grasping organ. The 
knee-joint is situated between segnents 18 and 1g. The 17th 
segment bears a toothed-plate which is prolonged distally over 
the 18th segment, which bears a toothed-plate carrying numerous 
needle-like teeth, and distally has a pair of sharp fang-like teeth. 
The roth segment bears two long spine-like tooth-plates armed 
with fine teeth on their anterior margins. 
The left antenna resembles that of the female. 
The -th pair of legs. The left leg consists of three segments 
and the right of four, as in other members of the genus; arising 
from the basal joint of the right leg is a well-developed process, the 
endopodite. 
