64 BULLETIN OF THE 



portion exceedingly slender. The inner flagellum is considerably longer than 

 the outer, reaches nearly to the tip of the rostrum, and is slender throughout. 

 The antennal scale is about three fourths as long as the carapax excluding the 

 rostrum, and near the base about a fourth as broad as long, but tapers distally 

 to an acute tip. The second segment of the peduncle of the antenna is armed 

 with a triangular tooth above the base of the scale and with a long spine below. 

 The flagellum is slender, and considerably longer than the carapax including 

 the rostrum. 



The mandibles (PI. XI. fig. 1) are nearly as in P. Montagui, though the 

 proximal segment of the palpus is much less dilated, and all the segments are 

 only sparsely armed with setse ; the mandibles are in fact more nearly as in 

 P. tenui2)es. The first maxillae (Fig. 2) are essentially as in P. Montcujui. Tlie 

 lol)es of the protognath and the endognath of the second maxilla (Fig. 3) are 

 nearly as in P. Montagui, but the scapognath is very different ; its posterior lobe 

 is short, broad, and evenly rounded, much as in P. tenuipes, while the anterior 

 lobe is much longer than the posterior, fully as broad, and with a broad and 

 truncated extremity ; both extremities of the scaj)hognatli are margined with 

 very long plumose setae, while those upon the edges between are short. The 

 first and second niaxillipeds (PI. X. figs. 2*, 2'') do not differ essentially from 

 those of P. Montagui. The external maxillipeds have well-developed exopods 

 about two thirds as long as the ischium, which is more than half the entire 

 length of the endopod ; the terminal segment of the endopod is considerably 

 longer than the penultimate, and tapers to an acute point. 



The legs of the first pair are more slender than the external niaxillipeds, and 

 do not quite reach to their tips. The right chelate leg (PI. X. fig. 2°) reaches a 

 little by the base of the antennal scale, and is rather stouter than usual in the 

 genus ; the merus and carpus are subequal in length, and the carpus is rather 

 obscurely divided into about eight segments, of which the proximal and distal 

 are much longer than the others ; the chela is very little shorter than the 

 carpus and much stouter, and somewhat swollen so that it is between a third 

 and a fourth as broad as long ; the digits are rather stout, slightly curved, and 

 more than a third of the entire length. 



The three List pairs of legs are slender, subequal in length, reach to about 

 the tips of the first pair, are armed with numerous seta2 and slender spines, 

 and the dactyli are slender, very slightly curved, and about a third as long as 

 the propodi. 



The first, second, fifth, and sixth somites of the abdomen are evenly rounded 

 above, but the third and fourth are armed with a sharp dorsal carina, most 

 conspicuous on the third somite, and in both somites projecting backward over 

 the succeeding somite in a prominent horizontal and acute tooth. The first 

 epimeron projects downward even below the second, which is orlncular and 

 about as broad as high ; the third and fourth epimera project backward in 

 evenly rounded lobes, but the fifth in an acute angle. 



The telson is about as long as the fifth and sixth somites together, narrow, 

 armed witli four pairs of dorsal aculei, and the triangular tip (PL X. fig. 2') 



