442 PROF. C. CHILTON ON DETO, A SUBANTARCTIC 



which it arises ; on the anterior segments, especially the first, the surface in 

 front of these tubercles shows a few irregular granulations ; epimera well 

 developed, not separated from their segments bj a suture, each with a faint 

 oblique ridge running outwards and backwards to the posterior angle, the 

 ridge best marked on the posterior segments. Pleon with surface smooth, 

 epimera of segments 3, 4, and 5 well developed ; last segment triangular, 

 its extremity rounded. 



Female. — Differs from the male in lacking the prominent tubercles on the 

 segments of the perseon ; surface of head and perseon granular, the position 

 of the tubercles on the perseon represented bj^ a granule slightly more 

 prominent than the others. Antennae rather more slender than in the male. 



Length 13 mm.j width 6*5 mm. 



Colour. Slaty grey, tips of tubercles and lateral portions lighter in colour, 

 some lighter markings also on the general surface. 



Habitat. Cape Peninsula, South Africa, on sea-shore ; two specimens in 

 the St. Petersburg Museum from " Africa " ; many specimens in South 

 African Museum from " Sea-shore at Sea Point, Cape Peninsula, H. M. 

 Lightfoot coll." 



Of this species I have seen many specimens of both sexes and of different 

 sizes. It is a smaller species than D. echinata, and does not present such 

 marked sexual differences, though the pointed tubercles or teeth on the 

 perseon are quite prominent in the adult male ; in the figure they are perhaps 

 made a little too prominent. 



The antenna of the male is shown in fig. 6 ; it is similar to that of 

 D. echinata, but has the joints of the flagelluni slightly longer. 



The upper lip (fig. 7) has the margin broadly rounded and fringed with 

 short set fie. 



The mandibles (fig. 8) have only about ten long bristles in the tuft 

 representing the molar tubercle, and these are almost smooth except 

 towards the end, but otherwise do not diff"er from those of D. aucMandia\ 



The lower lip (fig. 9) has the outer lobes with a slight notch near the 

 apex, inner lobes narrow and delicate. 



The first maxillse are normal. 



In the second maxilla (fig. 10) the outer lobe is nearly as broad as the 

 inner, but not so thickly setose. 



The raaxillipeds (fig. 11) have the palp not much longer than the masti- 

 catory lobe, which is oblong, truncate at the end, and bears near the inner 

 anoie a small hairy appendage like a short, stout, plumose bristle. 



The perseopoda (figs. 12 & 13) increase slightly in length posteriorly. 

 They are rather spiny ; the dactyl bears a long split seta longer than the 

 others, which appears to represent the dactylar seta, but it is not very 

 prominent, especially in older specimens. 



