3G2 Mr. P. W. Bassett-Smith on 



This species bears a resemblance to Cah'gus irritans, Hell.*, 

 having the double long-shaped posterior thoracic segment and 

 elongated biarticulate abdomen ; it may readily be differen- 

 tiated by its broader, more arched carapace and strong four- 

 jointed fourth pair of legs, besides many structural details; 

 the male too varies considerably. 



Female. — Colour pure white; oculi pink. 



Carapace strongly arched upwards, considerably broader 

 than long, narrowing rapidly anteriorly, posterior angles 

 rounded, posterior median lobe broad, sulcus on each side 

 moderately deep. Frontal plate narrow, its anterior edge 

 almost straight; lunula? at the outer end shallow, small com- 

 paratively to those of C. irritans. 



Anterior antenna} having the first joint about equal in 

 length to width of the lunule; second joint longer and club- 

 shaped. 



/Second antennae of the usual form, but the terminal claw is 

 more slender than in general. 



Hamulus anterior very small, slightly curved; rostrum 

 short. 



Palp elongate, curved, with blunted end and an apparent 

 corstriction ; but no bifurcation is seen near the extremity. 



Jirst niaxillipeds of the usual form. 



Second maxillipeds : these are very strong, the basal joint, 

 both in young and old, having a very strong bifid tooth near 

 the extremity of its inner border, to which the end of the 

 strong terminal claw approximates ; at the base of the latter 

 is a fine hair on the concave border. 



Lurcida of moderate size; a long base with parallel sides 

 and rounded extremity giving off direct two short, flattened, 

 slightly divergent branches with blunted ends, the aperture 

 between them being considerably more narrow than the length 

 of the branch. 



iirst peraopod has three short terminal claws, with three 

 lung plumose hairs on the under border of the last joint ; but 

 J have been unable to discover the usual simple bristle at the 

 angle. 



Second perceopod of the usual form, but the bent short 

 claws on the upper border of the first and second joints of the 

 outer branch are strong, and at the end of the last joint there 

 is a very small spur, with a stronger one deeply fringed with 

 fine hairs on the underside; plumose hairs from beneath as 

 usual. 



Third i eraopod : paddle-joints rather widely separated, the 



' Reise der Fregatte Novara,' pp. 177 179. 



