ioó 



broad, in the largest female that measures 160 mm., these numbers are ii 1 ^ mm - a °d 10 mm. 

 In younger specimens the antennal scale reaches as far forward, but appears a little less broad: 

 so e. g. in a young male, long 115 mm., the scaphocerite is 7 1 /., mm. long and 5 4 / ; mm. broad, 

 in the egg-laden female, measuring 130 mm., it is S 1 /, mm. long and 6*/ s mm. broad. Of Nephr. 

 Challengeri the scaphocerite is comparatively longer and its outer margin terminates in a 

 small spinule. 



The extemal maxillipeds (PI. IV, fig. 18 c) extend, both in the male and in the female, 

 about as far forward as the antennal peduncle. The outer surface of the ischium gradually 

 widens anteriorly, its slightly curved inner margin is faintly denticulate along its whole length 

 and carries a small acute tooth at the distal extremity, the inner margin is slightly concave 

 and bears a still smaller tooth distally. The inner margin of the inner surface is armed with 

 20 — 25 acute spines of different size. The merus is nearly as long as the preceding joint, its 

 inner margin is armed with 5 to 7 acute spines of different length, the distal spine being the 

 largest; the distal extremity of this joint is also acute. The lower margin of the carpus ends 

 distally in a small acute tooth. Propodus enlarged, a little more than twice as long as broad, 

 dactylus also depressed, its greatest wiclth one-third its length. 



Unfortunately the external maxillipeds of Nephr. Thomsoni have not been described by 



" Spence Bate ; his figure i on Plate XXVI, however, is probably inexact, for, when it is compared 



with the figure 18^ on Plate IV of this work, representing the outer foot-jaws of Nephr. 



Sibogae, these appendages should rather considerably differ, which in so closely allied species 



appears improbable. 



Of the adult male the legs of the i st pair are equal, 212 mm. long, somewhat longer 

 than the body. The merus, strongly compressed and flattened above, is armed with a sharp, 

 strong, compressed spine at the distal end of its inner margin and with a somewhat smaller 

 one at that of the upper border ; both margins are granulate, the granules are a little larger 

 than those of the upper and lower surface, that disappear posteriorly, especially on the upper 

 surface; usually 2 or 3, rarely 4 or 5, granules of the inner margin are a little larger than 

 the rest and more or less spiniform. The preceding joint, the ischium, appears both above and 

 below quite smooth, though slightly granular on its inner margin. The cylindrical carpus, which 

 is somewhat shorter than the merus, is everywhere granulated, the granules, however, are 

 on the inner side larger than on the outer; it bears 3 sharp teeth distally, one at the distal 

 extremity of the inner border, another somewhat more outwards, the third which is the smallest 

 of all, at the distal end of the lower border, while there is a fourth acute tooth at the base 

 of the outer border and a small obtuse tubercle on the upper surface not far from the articu- 

 lation with the merus. The chela is 125 mm long; the palm, 70 mm. long, gradually widens 

 towards the articulation of the fingers, where it is i6V 2 mm. broad, so that the palm appears 

 about 4-times as long as broad. The nearly straight, inner border of the palm is distinctly 

 granulate, the outer border of the chela appears slightly arcuate from the carpal articulation 

 to the end of the immobile finger; the outer border is somewhat flattened with the margins 

 more distinctly granulated. The upper and the lower surface of the palm are more coarsely 

 granulated on the obtuse crest that runs from the carpal articulation to that of the dactylus 



