386 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [42] 



concave and its dorsal edge strongly compressed and tbin, the digits con- 

 siderable shorter than the body of the chela, slender, tapering to very 

 slender and strongly curved tips, and the prehensile edges armed, ex- 

 cept at the tips, with a closely set uniform series of slender spiniform 

 teeth. The second pera^opods are about a third longer than the first : 

 the basis and ischium are armed with minute spines or teeth along the 

 lower edge ; the merus is about a third longer but scarcely stouter than 

 in the first pair, and the lower edge is armed with a series of several 

 acute spiniform teeth ; the carpus is scarcely longer than in the first 

 pair, but the lower distal angle is produced and spiniform ; the chela is 

 about a third longer than in the first pair and much more slender, being 

 absolutely narrower, and narrowed from near the base, the body is con- 

 vex on the outside and flat on the inside, and the digits are as long as 

 the body, with sharply curved tips, armed as in the first pair. The third 

 peraeopods are a little shorter than the first, exceedingly slender, sub- 

 cylindrical, naked, and unarmed : the merus is nearly half the entire 

 length; the carpus A'ery short; the propodus is more than half as long 

 as the merus, and tapers to a very slender tii) which bears a short seta- 

 like dactylus. The fourth pera^opods are about as long as the meri 

 in the third pair and very slender throughout; the merus is about a 

 third the length of the endopod, and about equal to the propodus and 

 dactylus taken together, while the dactylus is only about a fourth as 

 long as the propodus. The fifth perneopods are about a third longer 

 than the fourth and slender throughout ; the merus and propodus are 

 subequal and together make more than half the whole length, and 

 the dactylus is less than a third as long as the propodus. The exopods 

 of the first and second pairs are slightly longer than those of the second 

 gnathopods, while those of the three posterior pairs decrease in length 

 successively to the fifth pair, where they scarcely reach by the middle 

 of the merus. 



The pleon is about twice as long as the carapax, the three anterior 

 somites are higher than the carapax, with the dorsum evenly rounded 

 and the lower edges of their pleura horizontal and the angles rounded. 

 The fourth somite is armed with a dorsal carina, beginning at the mid- 

 dle of the somite and produced back over the next somite in a small 

 aud acute tooth; the lower edge of the pleuron is on a line with those 

 of the preceding somites, and its angles rounded or obtuse. The fifth 

 somite is only a little higher than the sixth ; the dorsum is flattened 

 and slightly sulcated; and the pleuron is truncated below, but the apices 

 of the angles are obtuse. The sixth somite is considerably shorter than 

 the antennal scale, about two-thirds as high as long, compressed, and 

 the dorsum rounded. 



The telson is about one-half longer than the sixth somite, has a dorsal 

 sulcus, but no dorsal or lateral aculei, aud is regularly tapered to a nar- 

 row, convex tip, armed with six to eight slender spines, of which the 

 lateral pair are much the larger. The inner lamella of the uropod is 



