26 



The species of Phreatoicus now under consideration may- 

 be described as follows : — 



Phreatoicus latipes, n. sp. 

 Figs. 1-14. 



Specific diagnosis. — Body stout. Peraeon (fig. 2) broad, 

 not laterally compressed, moderately convex with the pleural 

 portion of the first four segments projecting outwards and 

 slightly downwards so as to conceal the basal joints of the legs. 

 Pleon short, about half the combined length of the cephalon 

 and peraeon, moderately compressed laterally, pleural portions 

 of the segments produced downwards, their lower margins 

 being rounded and fringed with a few setae. First segment 

 of peraeon short and immovably joined with the head but with 

 the suture well marked, pleural portion of segment free and 

 produced anteriorly about half-way along the lower margin of 

 the head, those of the second and third segments less pro- 

 duced anteriorly. Eye well developed, irregularly rounded or 

 subtriangular, black. Surface of the body covered with small 

 scattered setae, nearly smooth but with slight wrinkles or 

 irregularities on most of the segments. Sixth segment of 

 peraeon united with the terminal segment, or telson, but 

 distinctly marked off from it by a well-defined suture running 

 obliquely backwards from the upper pleural portion of the 

 fifth segment to the base of the uropod (fig. 4). Terminal 

 segment strongly arched above, sides widely separate below, 

 the mid-dorsal end portion showing as a slight process in side 

 view and when seen fiom above having a median indentation 

 between two rounded lobes, each of which bears three or four 

 setules. (Fig. 3.) 



First antenna more than half the length of the second, 

 joints of the ftagellum not broadened. Second antenna nearly 

 as long as the head and first two segments of the peraeon. 



The mouth parts do not differ greatly from those of 

 Phreatoicus australis. In the mandibles the palp is rather 

 short', the third joint being quite short and bent at right 

 angles to the second. There are two strongly chitinized cut- 

 ting edges in the left mandible; in the right the inner one is 

 small and colourless, as in P. capensis. The first maxilla has 

 about six plumose setae at the apex of the inner lobe. In the 

 second maxilla the two outer lobes are very slender, bearing 

 long pectinate setae ; the inner lobe is broader and rounded, 

 densely setose, and fringed along its inner margin with a very 

 regular and distinct row of long setae. In the maxilliped, 

 the epipod is nearly circular, thin; the second joint bears a 

 very distinct row of plumose setae projecting inwards towards 

 the mouth cavity; the palp is of the usual structure. 



