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 filth 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. 1 c. 



All of the pleonal segments are plainly evident above, the fiirst 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. 2 c) 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 

 (PI. 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 cUiated and armed with short spinules. The inner is destitute of . 

 the emargination seen on the outer border near the tip in the other species. ' I 

 The second pair of pleopods in the male (PI. I. Fig. 2 d) 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, 7.5 mm. The single male specimen 

 obtained is smaller : length, 16 mm.; breadth, 5.5 mm. 



Cirolana impressa sp. nov. 



Plate I. Figs. 3- 3d. Plate II. Figs. 3 -3c. 



This species closely resembles C. polita (Stimp.), as may be seen from the 

 figiu-es 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. 



