400 Annals of the South African Museum. 



a sharp keel which forms the lateral margin of the animal when 

 viewed from above, below this keel the epimera are vertical. 



Pleon with a short 1st segment, almost concealed under 7th 

 peraeon segment, 2nd segment wider than the others, its rounded 

 pleura entirely concealing the epimera of the 7th peraeon segment 

 ventrally, 4th segment with 2 small subrnedian tubercles on 

 posterior margin ; telson with 2 low submedian carinae, outside 

 of which on either side is an elongate tubercle, and behind the 

 carinae 2 minute submedian tubercles. The distinctness of these 

 4 tubercles is very variable, in adult males they are often obsolete. 

 Sometimes also both the elongate .tubercles are divided into 2 

 circular tubercles. Apex acute, in the male with a narrow slit 

 widening anteriorly into an oval longitudinal foramen, in the 

 female entire with a dorsal longitudinal carina. In the young 

 male the apex is bifid with a narrow A-shaped groove on dorsal 

 surface. 



First antenna, 1st joint longest, with sharp carina on anterior 

 margin, 2nd joint shortest, flagellum shorter than peduncle, 12- 

 jointed. 



Second antenna, 3rd and 4th joints subequal, 5th longest, 

 flagellum a little shorter than peduncle, 14-jointed. 



Epistome short proximally rounded, the arms narrow ; upper lip 

 with slightly convex distal margin, setose. 



Lower lip with short, broad lobes, apices rounded setose. 



Mandibles, cutting-edge bluntly and obscurely tridentate, second- 

 ary cutting-edge in left tridentate, spine-row in both with ca. 8 

 spines, molar well developed, denticulate, with tuft of setules, 

 palp stout, 2nd joint not longer than 1st or 3rd, 1st slightly longer 

 than 3rd. 



First maxilla, outer plate with 10 spines, the inner ones den- 

 ticulate. 



Second maxilla, outer and inner plates both with 8 denticulate 

 setae. 



Maxilliped, outer margin of 2nd joint sinuous, inner plate length 

 of 2nd joint, slender, 1 coupling-hook, lobes of 4th-6th joints and 

 apex of 7th setose. 



First peraeopod, inner margin of 4th-6th joints with short, thick 

 fur, inner margin of 7th with blunt denticles. 



The other peraeopods similar to 1st, but becoming successively 

 longer and 5th joint nearly as long as 4th, not triangular. 



Male appendages on 7th peraeon segment short, some distance 

 apart, apices blunt. 



