370 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [26] 



is very slender, cyliudrical, and nearly naked, the distal segment is 

 about two-thirds as long as the middle, somewhat triquetral, very 

 slightly expanded near the middle, tapered to a point distally, and armed 

 with numerous short setse. The exopod is very slender and about three- 

 fourths as long as the proximal segment of the eudopod. The epipod 

 is rudimentary, scarcely longer than the breadth of the protopod, in a 

 transverse sulcus on the outer side of which it lies. 



The first four pairs of perajopods have exopods and epipods, like the 

 second gnathopods, but the exopods diminish in size very rapidly posteri- 

 orly and are minute upon the fourth pair. The first pair are nearly as 

 long as the carapax, including the rostrum, and reach to about the tips of 

 the antennal scales : the ischium is slightly longer than the merus, and 

 both are very slender and armed with a few small spines ; the carpus 

 is very much more slender than the merus, and about twice as long, 

 slightly enlarged at the distal extremity, and entirely naked and un- 

 armed ; the chela is about a fourth or fifth as long as the carpus, con- 

 siderably stouter, slightly flattened, and the digits nearly a third of the 

 entire length, slightly curved, and rather sparsely clothed with slender 

 setaB. The second are similar to the first, but very much longer and 

 more slender : the chela is about as long as in the first pair, but not 

 quite as stout, while the ischium, merus, and carpus are very much 

 longer than in the first pair. The third, fourth, and fifth pairs are nearly 

 alike, much longer than the second, and exceedingly slender : the iscia, 

 meri, and carpi are i)roportionally about as loug as in the second ; the 

 propodi are very shorty approximately a tenth as long as the carpi, and 

 slightly stouter ; the dactyli in the third and fourth pairs are a little 

 longer than the propodi, slender, acute, and surrounded at base and 

 almost hidden by a circle of very long and slender setae ; in the fifth 

 pair the dactylus is very short, about a fourth as long as the propodus, 

 but surrounded and hidden b^^ a circle of setae about as long as in the 

 third and fourth. 



The first and second somites of the pleon are broadly rounded above, 

 and not at all compressed, but the succeeding somites are considerably 

 compressed particularly near the dorsum, which is not really carinated on 

 any of the somites however, though the third somite is prolonged in a 

 broad and prominent tooth over the fourth. The first pleuron is broad 

 and evenly rounded below, the second much longer than high and ellip- 

 tical, the third and fourth with the posterior edges rounded, but the fifth 

 produced posteriorly in an acute point. The sixth somite is about twice 

 as long as the fifth, less than half as high as long, and very strongly 

 compressed. 



The telson is about as long as the sixth somite, narrow distally, 

 rounded above, and armed with five to ten pairs of dorsal aculei and 

 two pairs of long spines at the tip. The outer lamella of the uropod 

 reaches to about the tip of the telson, is nearly four times as long as 

 broad, with the rounded tip extending much beyoud the tooth, in which 

 the stout outer margin terminates, and just within which there is a spine, 



