394 DE. J. G. DE MAN ON CRUSTACEA CHIEFLY 



tlie oibits. The orbits are well developed but incomplete below ; the movable eye- 

 peduncles are of a stout shape, being a little more than half as thick as long; the red- 

 brown cornesB are distinctly facetted. Tbe eye-peduncles are a little pubescent, and 

 these minute hairs are, like those of tbe carapace, a little setose or ramified. Infraorbital 

 ridge smooth, prominent, running a little below the orbits. 



Epistome extremely sbort. Tlie buccal cavern broadens backward, as the slightly 

 arcuate lateral margins distinctly diverge ; posteriorly it is 2-5 mm. broad, little more 

 than one-third the greatest width of the carapace, and the buccal cavern appears once and 

 a half as broad as it is long. The greater median part of the anterior border of the 

 buccal frame is straight, whereas the smaller lateral parts are slightly convex. Palate 

 quite smooth, without any trace of a median or lateral ridges. 



The external maxillipeds are widely distant ; the greatest width of the gap, at the 



boundary between merus and ischium, is more than once and a half as large as the 



breadth of each footjaw at that jilace; these maxillipeds are rather feeble (lience the 



name of Asthenognathns), for they do not quite reach to the anterior border of the buccal 



frame, leaving a small gap between them and this border. The ischium is 0"72 mm. 



long, quadrangular, its slightly concave anterior border is 0"38 mm. broad; it becomes 



somewhat broader backwards, so that it is 06 mm. broad in the middle; the ischium 



appears thus a little longer than broad in the middle. The slightly arcuate inner border 



is granulate, and one observes on its outer surface a shallow groove that runs nearer to 



the inner than to the outer border, with which it is parallel. The merus- joint is also 



quadrangular, but smaller than the ischium, for it is only 0"62 mm. long between the 



antero-external angle and the posterior border ; this joint, 0o4 mm. broad in the middle, 



is but little longer than broad ; the outer margin runs at first parallel with the somewhat 



arched inner (PL 31. fig. 4), but then it runs inward towards the ischium, so that it shows 



an obtuse angle in tlie middle. The anterior border of the merus is barely broader than 



the posterior, viz. 04 mm., makes right angles both with the inner and outer margins, and 



the antero-internal angle is rounded ; a longitudinal groove runs, on tlie outer surface, 



near and parallel with the inner border along the whole length of the merus-joint. The 



palp is of moderate size and articulates near the antero-external angle of the merus ; it 



consists of three joints that articulate at their distal ends. The carpus, 0'55 mm. long, 



measured along its outer border, is a little shorter than the merus and nearly twice as long 



as the follow ing joint ; the terminal joint is 0"38 mm. long, almost three times as long as 



thick at base, conical or rather sugarloaf-shaped ; it is furnished with long setae, and the 



inner borders of ischium and merus are also setose. The exognath, which is not concealed, 



reaches almost to the distal third or fourth of the outer border of the merus ; near the 



middle of the ischium it is 0'23 mm. broad, about one-third of the breadth of this joint, 



but it distinctly narrows anteriorly. The gap between the outer footjaws is a little 



broader between tlie antero-internal angles of the merus-joints than at the base of the 



ischium-joints. The anterior border of the sternum is coarsely granulate. 



The abdomen is 7-jointed and 5'6 mm. broad, a little less than the upper surface 

 of the carapace ; the penultimate joint of the abdomen, which is finely punctate and 

 pubescent, is 0'88 mm. long, measured in the middle line, whereas the antepenultimate 



