38 



is almost flat. The frontal margin is produced into a horn on 

 each side of the rostrum ; each horn ends sharply in a short 

 spine and also bears a few small spines on its sides. Immediately 

 beneath the rostrum, which is formed of two spines, there is 

 a single median spine directed downwards. The gastric surface 

 slopes downwards very steeply, almost vertically, to the ros- 

 trum. The hind margin of the carapace is concave. The spines 

 of the median carina are arranged thus : — ■ 



Rostrum+1, 1, 1, 2, 1 ; 2, 2, 1, 2. 



On the front part of the lateral margin there are seven or 

 eight spines, in the middle five or six, and posteriorly, from 

 seventeen to twenty. These latter increase in size towards 

 the hind margin. The branchial carina consists of ten or eleven 

 spines. The upper submarginal carina has six spines at the 

 posterior end, practically disappears in the middle, but is 

 continued anteriorly as a low ridge bearing a large number of 

 spinules, and ending in a strong spine opposite the base of the 

 antenna. The lower submarginal carina has twelve or thirteen 

 spines, extending almost to the base of the chelipeds ; they are 

 not quite so large as those of the upper row. Along the edge 

 of the upper part of the cervical groove there are three or four 

 sharp spines. As already mentioned, the intercarinal spines 

 are most plentiful above the branchial ridge, less common 

 between the latter and the lateral margin, and practically 

 disappear below this. The setae are most plentiful on the carinae. 



The median spines on the abdominal segments are arranged 

 as follows : — 1, 3, 3, 3, 3, 1, 1, the last on the base of the telson. 

 In addition to these the segments bear other spines. On the 

 sixth there is one at each postero-lateral angle, and one at each 

 edge of the tergum, and a very small one just in front of this. 

 The fifth has one at each side of the tergum, with a smaller 

 one in front of it, and one on the middle of each pleuron. On 

 the second, third, and fourth segments there is likewise a spine 

 at each lateral end of the tergum, and one on each pleuron, 

 and on the second and third only, a single spine on the tergum, 

 between the median line and the edge of the tergum. 



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

 in the second segment they are broad and expanded, and on 

 their lower margin they have a row of spinules. The third, 

 fourth, and fifth pleura are narrowed, and have each five or 

 six small spines at their extremities. In the sixth segment the 

 pleura end in a single narrow tapering point. 



The telson has a row of seven or eight spines along each margin, 

 but none on its dorsal surface. 



There is a short, blunt tubercle on the front of the eyestalk. 

 The eyestalks do not quite fill the wide orbital sinuses. 



The antennular scale ends in a narrow spine, not quite reaching 

 the end of the peduncle. Its inner margin bears five or six 

 spines, and also pinnate setae. At the outer angle of the basal 

 peduncular joint there are two spines. The third joint is shorter 



