394 EEPOKT OF COMMISSIONER OF FISH AND FISHERIES. [50] 



tion, slender, very slightly curved at the tips, and the prehensile edges 

 setigcrous. 



The second peraeopods are much like the first, but a little more slender 

 and considerably longer, reaching to the tips of the peduncles of the 

 antennae ; the merus and carpus are apijroximately equal in length, and 

 narrower than in the first pair, and the chela is considerably shorter 

 than the carpus. 



The third perseopods reach beyond the middle of the antennal scales, 

 are more slender than the second pair, and naked except at the tips of 

 the digits : the ischium is shorter than the merus, and both these seg- 

 ments are very narrow and slightly compressed ; the carpus is about as 

 long as the merus, or a little longer, and subcylindrical ; the chela is 

 about half as long as the carpus, very slender, scarcely stouter than the 

 carpus, and the digits slightly more than half the whole length. 



The endopods of the fourth peraeopods are wanting or imperfect in all 

 the specimens. They are very slender, and, exclusive of the dactyli, 

 considerably longer than the third pair : the ischium and merus are 

 slightly compressed and setigerous along the inner edges ; the carpus 

 is a little shorter than the merus, and both the carpus and propodusare 

 throughout cylindrical, exceedingly slender, much more slender than 

 the distal end of the merus, and naked. 



The fifth peraeopods are wanting in all but one specimen, and in this 

 only one of them is complete. This peraeopod is like the fourth pair, 

 but even more slender, and about as long as those of the third pair: 

 the carpus and propodus are subequal in length and each is a little 

 shorter than the merus ; the dactylus is a little shorter than the pro- 

 podus, very slender, cylindrical, rather suddenly tapered at the tip, 

 which is armed with a few setae, and is not hard and chitinous, but ap- 

 parently somewhat soft and flexible. 



Tliere are no exopods at the bases of any of peraeopods. 



The pleon is slightly more than twice as long as tLe carapax, ante- 

 riorly about as broad as high, but much compressed posteriorly, so that 

 the sixth somite is fully twice as high as broad. The dorsum is evenly 

 rounded on the first four somites, but there is a narrow and sharp car- 

 ina oa the fifth and sixth, which upon the middle of the fifth is armed 

 with a very slender spiniform tooth projecting back as far as the i)os- 

 terior edge of the somite. This tooth is broken in nearly all of the 

 specimens, and in the specimen from the Blake dredgings was wholly 

 wanting, having undoubtedly been broken off close to the base. The 

 posterior prolongations of the first and second pleura are broadly 

 rounded; those of the third and fourth less broad and more angular, 

 but still obtuse and rounded at the posterior angle ; while the fifth is 

 acutely angular, but with the tip itself obtuse. The sixth somite is 

 twice as long as the fifth, and more than half as high as long. 



The telson is shorter than the sixth somite, narrowly triangular, 



