116 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
posterior portion, yet not extending to the posterior margin. The pleural plates 
are comparatively large, oblong, rounded, thus occupying the whole or at least 
most of the lateral margin; in the posterior segments they are broader and. 
overlap each other considerably ; their convex ventral side with numerous 
small tubercles and oblong knots. The three posterior segments on the ventral 
side with an interrupted row of very short fleshy keels ; the other segments 
are not examined. The legs are robust; the second joint (Fig. 1b and 1 d) 
on the outer side with a very high expansion, shaped as an oblique plate, which 
is about as high as long and somewhat shorter than the length of the joint, on 
both sides with irregular small protuberances ; the other joints normal. In 
Figure 1 b is shown the first left leg with the marsupial plate ; this plate shows 
on the under side a deep transverse furrow and more forward a group of low 
knots, on the upper side (Fig. 1 c) a kind of transverse keel, the marginal por- 
tion of which is divided into numerous irregular, small, thin-skinned processes. 
The basal part of the other four pairs of plates with numerous knots (Fig. 1 a). 
(The marsupium of both specimens with eggs.) 
Abdomen. The five anterior segments with very large rounded pleural lamelle, 
the anterior of which are somewhat transverse, the posterior oblong; the lamelle 
cover the main part of one another, a large portion of the dorsal surface of the an- 
terior segments, and the whole dorsal surface of the posterior ones. In Figure 1 
the fifth pair of lamelle are lettered a5, The second to the fifth segments on 
the ventral side each with a transverse row of short fleshy processes or knots, 
or lamellar keels; the first segment with an interrupted series of low lamelle. 
The sixth segment (posteriorly behind the attachment of the uropods produced 
into an oblong, distally rounded and swelled, almost petiolated process. Each 
pair of pleopods consists of two large rami; in the anterior pairs these are 
shorter and rather broadly triangular, backwards they gradually become elon- 
gate. The uropods biramous, the rami similar to those of the last pleopods ; 
in Figure 1a the visible distal part of the rami on the left side of the figure 
are marked with 6, on the right side with 61. The main part, or almost the 
whole, of both surfaces of the pleural lamell® and of the pleopods and uropods is 
set with very low and irregular minute keels and more rounded protuberances, 
which are most developed on the anterior pleopods. 
Size. The largest specimen — which has been taken as type for all the fig- 
ures — is 14.2 mm. long to the end of the abdomen, 17.3 mm. long to the apex 
of the longest ramus of the uropods, and 10.9 mm. broad. The other specimen 
measures 15.6 mm. to the end of the uropods. 
b. Male. 
One specimen (Plate IV. Fig. 25) is symmetrical and undoubtedly normal ; 
the other specimen (Fig. 2c) is anomalous, not symmetrical, and somewhat 
misshapen, — especially the abdomen is conspicuously different. In the fol- 
lowing the normal specimen is described, with some remarks concerning the 
other. 
