94 BULLETIN OF THE 



seven or eight times as long as broad ; the carpus is a third or fourth shorter 

 than the ischium, but as broad ; the chela is slightly stouter than the carpus 

 and only a little shorter, and has slightly curved digits about two thirds of the 

 whole length ; the lower edges of the ischium, nierus, and carpus are armed 

 with fascicles of long spines and setae as in the external maxillipeds, the upper 

 edges of these segments and both edges of the chela are armed with much 

 smaller spines or setae, and in addition there is a small area densely covered 

 with very short setse or hairs near the distal end of the lower edge of the carpus, 

 and a similar area in a corresponding position at the proximal end of the chela. 

 The second legs are a half longer and much more slender than the first, nearly 

 cylindrical, reach to the tips of the antennal scales, and are almost entirely 

 naked. The third legs (PL XV. fig. 11) are like the second, but longer, 

 reaching to the tips of the external maxillipeds. The chelae of the second 

 and third pairs are about as long as those of the first, but more slender, with, 

 proportionally shorter, straight and weak digits, and naked except for a few 

 very minute hairs near the tips of the digits. 



The fourth and fifth pairs of legs are exceedingly long and slender, and appar- 

 ently very nearly alike, but the distal segments are wanting in all the speci- 

 mens seen ; the meri, however, reach to about the tips of the antennal scales 

 in both pairs, but in the fifth pair a little farther than in the fourth ; and the 

 parts which are preserved are almost entirely unarmed. 



The branchiae appear to be less densely branched than in the typical species 

 of Penctms, and there are two arthrobranchiae at the base of the penultimate leg 

 each side instead of one, making nineteen branchiae on each side arranged as 

 indicated in the following table. 



Somites. 

 Epipods, 

 Podobranchias, 



VII. 



1 

 



VIII. 



1 

 1 



IX. 



1 







X. 



1 







XI. 

 1 

 



XII. 

 1 

 



XIII. 

 1 

 



XIV. 

 

 



Total. 



(7) 

 1 



Ar throbran chi 33, 





2 



2 



2 



2 



2 



2 







12 



Pleurobranchiae, 











1 



1 



1 



1 



1 



1 



6 



19-K7) 



The abdomen to the tip of the telson is slightly more than once and a half as 

 long as the carapax including the rostrum, anteriorly nearly as broad as the 

 carapax, but strongly compressed back of the third somite so that the sixth 

 somite, which is nearly a fourth of the entire length of the abdomen and nearly 

 twice as long as high, is nearly twice as high as broad. The three anterior 

 somites are evenly rounded above, but the three posterior are sharply carinated, 

 and on the fifth and sixth somites the carina terminates at the posterior margin 

 in a small tooth. The epimera of all the somites are rather small, and have the 

 posterior angles more or less rounded. 



The telson is not quite perfect at the tip in any of the specimens, but is nearly 

 three fourths as long as the sixth somite, narrowly triangular, thickened at base, 

 lias shallow dorsal and lateral sulci nearly the whole length, and the lower edge 

 each side is armed near the tip with a slender spine. 



