36 



Second Segment. — Central double spine ; one large spine at each 

 side of tergum, and one large and one small on each 

 side of posterior margin. 



Third Segment. — Central double spine ; one at each side of 

 tergum, one on each pleuron, and one small spine on 

 each side of middle of posterior margin of tergum. 



Fourth Segment. — Central double spine ; one at each side of 

 tergum, two on each pleuron, and two small ones on 

 each side on posterior margin of tergum. 



Fifth Segment. — Central double spine ; one at each side of tergum, 

 and two on each pleuron, near the posterior edge. 



Sixth Segment. — Central single spine; one at each side of tergum, 

 and one at upper posterior angle of pleuron extending 

 over base of uropods. 



In the double spines the anterior point is the larger, and it 

 is more or less erect, though often curving backwards near 

 the tip ; the posterior halves are inclined at an angle of about 

 forty-five degrees to the horizontal. 



The pleura of the first segment are very small and narrow\ 

 Those of the second segment are broader than any of the others ; 

 their lower margin is rounded and bears a row of small teeth. 

 In the third and fourth segments the pleura taper shghtly 

 downwards, and are also furnished with teeth near then- ex- 

 tremities. The fifth pleura are very narrow and end in a long 

 spine in front of which are one or two teeth. In the sixth segment 

 they are narrower still and taper to a needle-like point. 



The tslson bears a single large median spine near its base, 

 and tapers to a sharp point. Its edges bear small spines, and 

 are also fringed with setae. There are no spinules on the dorsal 

 surface. 



The median line of the abdominal segments bears a number 

 of stiff seiae scattered about the bases of the large spines. 



The eyestalks bear a small tubercle on the anteiior margin ; 

 they do not completely fill the orbital sinuses. 



The basal joint of the antennular peduncle has only a single 

 spine at its outer anterior angle. The scale ends in a sharp 

 in turned point and has six or seven spines on the inner edge. 



The antennal scale is narrow and has a rounded tip ; it is 

 fringed with sstae, and reaches to the end of the peduncle. 



The chelipeds are shorter than the body. The merus is 

 spinulose on both margins, and has the usual distal spine. The 

 carpus has an upper and a lower distal spine. The margin of 

 the propodite is spinulose from the proximal end to the base 

 of the dactyl, where there is a single spine. The basus bears 

 a spine just below the beginning of the ischium. 



The second pereiopods are much stouter than the succeeding 

 pairs, but shorter and slenderer than the chelipeds. The merus 

 is slightly thicker in its distal portion than near the base ; 

 slightly more than half-way to the distal end it bears three 

 large and three or four small spines on its outer margin ; at 



