Contributions to the Crustacean Fauna of South Africa. 227 



less strongly expanded, both 5th and 6th joints with plumose setae 

 on both margins, 3rd joint with a few plumose setae on posterior 

 margin, 7th joint as long as width of 6th, very slender, margins 

 minutely setulose, apex with 2-3 setae. 



Male appendages on 7th segment narrow, slender, distal three- 

 quarters thread-like, not extending beyond the first pleopods. 



First pleopods $ , long and narrow, not apically expanded, rami 

 projecting a little beyond the apices of peduncles. 



Operculum $ evenly rounded and without (or with very indistinct) 

 keel. 



Second pleopods $ , strongly contracted near the apex, male stylet 

 barely longer than peduncle. 



Third pleopods, outer lobe 2-jointed, narrow, strongly curved but 

 hardly reaching beyond apex of broad inner lobe. 



Fourth pleopod consists of 2 broad rather wrinkled lamellae, the 

 anterior one being smaller and fitting within the posterior one, which 

 fits within the still larger and similarly wrinkled fifth pleopod, which 

 consists of only a single lamella. 



Uropods small, peduncle barely projecting beyond margin of pleon, 

 inner ramus as long as peduncle, with 2 apical spines, outer ramus a 

 little longer, with 3 apical spines and a few setae. 



Length : 3 11 mm. $ 14 mm. ; breadth : $ 4 mm. $ 5 mm. 



Colour : In spirit, whitish or faintly pinkish. 



Locality : Lion's Head SE. J S. distant 50 miles, 230 fathoms ; 

 24 $ ? (some with ova) and 4 $ $ . 2/4/02. Cape Point NE. 

 distant 40 miles, 560-700 fathoms ; 1 mutilated specimen. 17/9/03, 

 s.s. " Pieter Faure." (S.A.M. Nos. A1614 and A2458.) 



This species is very near to the type species M. arcticus, 

 Eichardson, but differs in the following characters : 



There are no dorsal tubercles on peraeon segments 5-7 and the 

 pleon is evenly rounded, not produced into a median lobe. 



The mandibles have more strongly developed molars and the left 

 cutting-edge is bilobed. 



Inner lobe of the first maxilla has 2, not 3, spines ; and the spines 

 on outer and middle lobes of the second maxilla are long and pointed, 

 not short and blunt. 



The sixth joint of the maxilliped is strongly expanded, not parallel- 

 sided as represented in Kichardson's figure. 



The second pleopod in the male is distally narrowed, the outer 

 margin not being evenly convex. 



The uropods have apical spines instead of being rounded. 

 M. arcticus is recorded from Nova Zembla. 



