HANSEN: THE ISOPODA. 121 
Cymothoide. ‘The posterior portion of the lateral part of the segments men- 
tioned is more or less protruding, rounded or angular, and must be considered 
as the posterior division of the pleural plate (compare Cryptione). On the 
three posterior segments the pleural plates are deeply incised, divided into a 
larger, broader, and more produced anterior part, and a much smaller, nar- 
rower, and less produced posterior one, which is more or less obsolete on the 
last segment. At least on the posterior segments the ventral side shows the 
usual low fleshy keels. The legs are slender ; the second joint proximally on 
the outer side with a considerable rounded expansion, which is comparatively 
longer and broader on the anterior (Fig. 1d) than on the posterior (Fig. 1e) 
pairs; the other joints are normal. In Figure 1d is shown the first leg with 
its unusually large marsupial plate; the transverse furrow is not deep; on 
the upper side the keel is tolerably high and much compressed, but without 
marginal processes. The marsupial plates do not quite reach each other at the 
middle ; their natural position was somewhat disturbed in the specimen, and 
therefore it was necessary to make use of construction in Figure 1a. 
Abdomen. The segments distinctly separated at the middle on the flat dorsal 
surface, No pleural plates. The segments fleshy on the ventral side ; only 
the first segment with slight furrows. The pleopods very curious, and rather 
similar to each other; each consists of two rami; the outer ramus is a very 
long, subrectangular or distally rounded, somewhat fleshy lamella, which is 
placed at the margin of the segment ; the inner ramus is proportionally short, 
more or less ovate, fleshy, originating at some distance from the outer ramus, 
and on the left side of the animal it conveys the impression that the basal half 
is fused with the ventral side of the segment. (I am aware that another 
interpretation of the described facts could be advanced, namely, that the outer 
ramus is a pleural plate set off by a kind of articulation, and that the inner’ 
ramus in reality represents the entire pleopod, but this opinion I cannot share.) 
Each uropod consists of a single lamella of about the same shape and size as 
the nearest outer ramus of a pleopod. 
Size. The specimen is 8.5 mm, long to the apex of the abdomen, 10.3 mm. 
long to the end of the uropods, and 7.2 mm. broad. 
b. Male. 
The shape of the body is interesting. It increases uniformly but rather 
slightly in breadth from the head to the last thoracic segment, and the abdomen 
is anteriorly somewhat broader than the preceding segment, triangular with 
rounded angles, somewhat broader than long, the anterior margin a little con- 
cave and the lateral margins convex. The body is a little more than 2} times 
longer than the width of the abdomen. 
Head. The dorsal surface is convex, the median part of the anterior outline 
almost straight. A pair of small spots or minute depressions perhaps represent 
the eyes. When the head is seen from below (Fig. 19), it is observed that the 
frontal border arises like a broad and rather high transverse keel above the 
‘attachment of antennule and antenne. The antennule of medium length, , 
