194 



proximally, slightly concave in i t s anterior half, shows therefore its greatest 

 height ncar the base, a little less than one-sixth the length, and gradually becomes lower 

 anteriorly. Both the upper and the lower border of the rostrum end in a small acute 

 tooth; that of the upper is half as long as the tooth into which terminates the lower, reaches 

 not so far forward and a tuft of setae are implanted in the notch between the two teeth. 

 According to the figures in Paulson's work (Recherches sur les Crustacés de la Mer Rouge, 

 Kieff, 1875, PI. XIV, fig. 5) and in that of Nobili (1. c. PI. 5, hg. 1) the rostrum of Nikoides 

 Datiac shows a different form, the lower margin appearing slightly concave along its whole 

 length and the apical teeth being comparatively larger. 



Outer orbital angle rounded or obtuse, antennal spine small, acute, antero-inferior angle 

 of carapace rounded. Carapace smooth, without furrows. The abdomen, which, without the 

 telson, appears nearly 4-times as long as the 3 rJ somite is high, is also smooth and closely 

 resembles that of Proc. canaliculata Leach, four specimens of which from the Gulf of Naples are 

 lying before me. Like in this species the straight lower margin of the pleura of the 5 th somite 

 terminates posteriorly in a minute acute tooth, while there are two spines at either side of the 

 6 th , one on either side of the posterior margin, the other at the posterior extremity of the 

 lower. The telson (Fig. 50^), which in the largest specimen appears half as long as the carapace, 

 rostrum included, and nearly one-third the rest of the abdomen, tapers rather considerably 

 backward, more than that of Proc. canaliculata; the greatest width, anteriorly, is a little more 

 than one-fourth the length and 3,7-times as broad as that of the tip; the telson is distinctly 

 grooved, but the groove fades away at the anterior sixth and it appears setose along its whole 

 length. The dorso-lateral spinules are 0,32 — 0,34 mm. long; the distance between the anterior 

 pair and the posterior margin of 6 th somite measures in the egg-laden female from Stat. 260 

 a little more than one-third the whole length, in the larger female from Stat. 274 slightly more 

 than twö-fifths, but in the younger specimens one-third or one-fourth, while the distance of the 

 posterior pair from the 6 th somite measures in the female from Stat. 260 a little more than half, 

 in the younger specimens two-thirds the length of the telson. On each side the tip (Fig. 50 tf) 

 of the telson bears 2 spines, of which the inner is 3-times as long as the outer; between the 

 two inner spines one observes at either side 4 setae, the lower of which is feathered and as 

 long as these spines, while the three others, implanted on the upper side of the rounded apex, 

 are shorter and simple. The specimen from Stat. 7 1 shows, as regards the tip of the telson 

 (Fig. 50/), a remarkable variety: between the two inner spines occur three other ones of sub- 

 equal length, about half as long as the former, and feathered. 



Eyes large, contiguous, almost as broad as long. 



Antennular peduncle slender, distance from the orbital margin to the far end of basal 

 article one-third longer than the 2 nd and 3 ld joint combined; i st joint deeply excavate, 2 nd joint 

 in the female from Stat. 260 3, 4-times as long as thick and twice as long as 3" 1 ; stylocerite 

 very short, lamellate, concave above, with sharp rounded anterior margin. 



Second joint of antennal peduncle unarmed, peduncle reaching to the distal third or fourth 

 of the 2 nd joint of that of the upper antennae; scaphocerite a trifle longer than the antennular 

 peduncle, nearly half as long as the carapace, rostrum included — 7,2 mm. long in the female 



