﻿150 Annals of the South Afncan Miisciiiii. 



MAKROKYLINDRUS, n. g. 



Cai-apace denticulate; no distinct eye; telson elongate, basal 

 portion cylindrical, much longer than the short post-anal portion, 

 which carries only the two apical spines. Perteopods of the female, 

 so far as known, without rudimentary exopods on the third and 

 fourth pairs. 



Name compounded of fiuKpog, long, and k-uXivcpog, a cylinder. 



It seems convenient to assign to this genus, besides the new 

 species M. fmgilis, four species previously placed under Diastylis 

 and one doubtfully assigned by Bonnier to Diastylopsis, so that 

 Makrokylindrus will contain M. Josephines, described by Sars in 1871 ; 

 M. erinaccus (Sars), 1837 ; M. dtihitis (Bonnier), 1896 ; M. cingulatus 

 (Caiman), 1905 ; M. serricauda (Scott), 1912 ; and M. fragitts, n. sp. 



Makrokylindrus fragilis, n. sp. 

 Plates LIV., LV. 

 The integument displays conspicuously a network of hexagonal 

 cells, regular or irregular, with a few smooth spots on the sides of 

 the pedigerous segments. The pseudorostral lobes are subacutely 

 produced in front of the prominent rounded but seemingly sightless 

 eyelobe. Along the line of junction there is on each side a dorsal 

 series of spines successively smaller to the rear, more numerous in 

 the male than in the female. The processes overhang the peduncle 

 of the first antennae to the end of its second joint ; a receding con- 

 vexity joins the lower margin without any projecting corner. 

 Behind the eyelobe a central ridge, elevated at the middle, ascends 

 to a bilobed girdle which crosses the carapace a little behind the 

 middle. Each lobe of the girdle descends forward to a point at 

 which it meets a dentate carina diverging upwards from the base of 

 each pseudorostral process ; from the same point a ridge descends 

 almost perpendicularly towards the lower margin, but before reach- 

 ing it divides, sending a short branch forward to the base of the 

 pseudorostrum and a somewhat longer one backward to the lower 

 margin. Behind the slightly advanced median point of the girdle 

 the dorsal line of the carapace undulates in gentle descent to the 

 hind margin in the female, with smooth curve in the male. First 

 and second pedigerous segments short, the first partially covered, 

 third and fourth dorsally coalesced but laterally distinct, with 

 considerable rounded dilatation of the side-plates of the third seg- 

 ment, fifth comparatively long, the hinder angles rounded. First 

 three segments of pleon in the male each with a pair of small dorsal 



