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Show 138 MR. R. I. POCOCK ON THE SCORPIONS [Mar. 18, large blunt tubercles: manus very wide, wider than brachium, almost wholly smooth, not carinate and not granular; movable dactylus half as long again as the " hand-back," bearing a distinct though small internal basal lobe which fits into a corresponding hollow in the immovable dactylus, so that when closed a sinuate space is left between them at the base ; the internal series composed of nine sharp separated teeth, the external series of eight pairs of teeth. Chelicerce. The movable dactylus armed above with three strong teeth, whereof the posterior is bifid, and below with two sharp teeth ; the two inferior teeth of the immovable dactylus well developed though smaller than the other teeth of this appendage. Legs. Femur and patella anteriorly finely granular ; the femur of tbe three posterior pairs carinate above and below, the patella of all of them carinate anteriorly ; tibice of the fourth pair armed distally with a spur, tibiae of the other pairs unarmed ; coxce smooth. Pectines projecting considerably beyond the distal extremity of the fourth pair of coxae, bearing 19 or 20 similar teeth. (The left pecten presents the curious abnormality of having the two apical teeth united.) Stigmata slit-like. Measurements in millimetres of (d) specimen..-Total length 59 ; cephalothorax, length 7"5, width 8 ; distance of eyes from posterior margin 4'5 : length of tail 42; of 1st segment 5 ; of 2nd 6 ; of 3rd 6-7 ; of 4th 7'5 ; of 5th 8'3 ; of vesicle 4-5 ; width of 1st 4-3 ; of 3rd 4'5 : of 4th 5"7 ; of 5th 5 ; of vesicle 3*3. Palpi-humerus, length 7 ; brachium, length 7'7 ; width 3 ; manus, width 4*5 ; length of " hand-back " 6*3 ; movable dactylus 2. A single specimen ticketed W . Africa, from the collection of Dr. (now Sir John) Kirk. This species differs from R. dentatus in having the under surface of third, fourth, and fifth caudal segments smooth ; in R. dentatus they are described as thickly granular. From R. biittneri1 it differs in having the keels on the tail much more feebly developed and in having no granular keels on the hand. RHOPTRURUS JACKSONI, sp. n. (Plate XIII. fig. I.) Colour of cephalothorax and abdominal tergites fusco-ochraceous, the central and lateral eyes and lateral margins of the cephalothorax and tergites dull black. Chelicerce infuscate distally above ; dactyli oi palpi infuscate, yellow only at the tips ; aculeus black in its hinder half; the rest of tbe animal, i. e. tbe legs, tail, palpi (all but fingers), and lower surface of the trunk, clear ochraceous. Cephalothorax very lightly and widely emarginate in front ; its posterior width considerably greater than its length ; almost wholly covered with coarse granulation, some smooth tracts extending 1 Since the above was written the Museum has received two female specimens of B. biittneri from Eio del Bey, W . Africa. |
