MUSEUM OF COMPARATIVE ZOOLOGY. 93 
the segment, and others in less regular order between this row of spines and 
the palmar border. In the English specimens these spines are even somewhat 
more numerous than in ours. The fifth leg is similar to the fourth, but some- 
what longer and more slender, and the spines on the merus and carpus are 
nearly as pronounced and definitely arranged as in the fourth, while a similar 
arrangement is found in a less degree upon the remaining two pairs of legs. 
In the last two pairs of legs the bases are flattened, expanded, and well ciliated, 
forming strong swimming organs. One of the last pair is figured on Plate II. 
Fig. le. 
All of the pleonal segments are plainly evident above, the first not being at 
all concealed by the last thoracic segment, as in the other species on our coast. 
The first four segments are subequal in length on the median dorsal line ; lat- 
erally they are carinated, the carina ending behind in an angulation (see Pl. I. 
Fig. 2c) which is most pronounced on the third segment and is rounded off 
on the fourth, The thickened, chitinous walls of these segments are more or 
less continued below the lateral keel upon the inferior surface of the pleon, and 
in the first two segments the inner and posterior angles of this portion are 
acutely produced, in the second segment, into short, divergent spiniform pro- 
cesses. In the third, the under part of the segment runs out to its lateral 
angle, and in the fourth segment this portion is small and not angulated. 
All these segments are smooth and not ciliated laterally. The fifth segment 
is small, and does not reach the lateral margin of the pleon. The last segment 
(Pl. II. Fig. 1) is semioval, acutish at the tip, near which it is ciliated and 
bears a few short spines. The basal segment of the uropod is produced at the 
inner angle to about half the length of the outer ramus. This ramus is lan- 
ceolate in outline, shorter than the inner, and of only about half its width; 
both are ciliated and armed with short spinules. The inner is destitute of 
the emargination seen on the outer border near the tip in the other species. 
The second pair of pleopods in the male (Pl. I. Fig. 2d) is armed, on its 
inner ramus, with a stylet of peculiar form. The stylet is slightly longer 
than the ramus and very acute at the tip, just below which it is suddenly 
much expanded and sends off a prong on the outer side, toward the lamella, 
as shown in the figure. A similar structure is seen in the male from the Shet- 
land Islands, but I have seen nothing like it in the other American species. 
Length of female, 23 mm.; breadth, 7.5mm. The single male specimen 
obtained is smaller : length, 16 mm.; breadth, 5.5 mm. 
Cirolana impressa sp. nov. 
Plate I. Figs. 3-3d. Plate I. Figs. 3-3e. 
This species closely resembles C. polita (Stimp.), as may be seen from the 
figures of the two species (Pl. I. Fig. 1, C. polita, Fig. 3, C. impressa). They 
are most readily distinguished by the impressed lines on the surface of the 
epimera in the present species, but a closer inspection brings to light other 
characters, as will appear in the following description. 
