292 THE TANGANYIKA PROBLEM. 



hepatic spines are present on the carapace, the surface of which is elsewhere smooth. 

 The third maxillipeds extend beyond the peduncle of the antennas by the length of 

 their last joint. The first perseopods (Fig. 21) extend to or a little beyond the tip 

 of the antennal scales. The carpus is rather longer than the merus, and more than 

 half as long again as the hand. 



The second peraeopod of a male specimen (Fig. 22) is about two-thirds the length 

 of the body, and the distal end of the merus extends to beyond the middle of the 

 antennal scale. The carpus is equal in length to the merus, somewhat expanded 

 distally, where the breadth is about one-fifth of the length. The hand is rather 

 wider than the distal end of the carpus, not perceptibly compressed (the two 

 diameters are about as 5 : 6), a little less than twice the length of the carpus. 

 Palm shorter than the carpus, and rather shorter than the fingers. Fingers straight, 

 meeting along their whole length ; inner margins with smooth cutting-edges, 

 without any trace of teeth save a single very minute tubercle near the base of the 

 dactylus. The surface of the whole limb bears widely-scattered very minute setae ; 

 on the distal part of the carpus and on the inner side of the palm are a number of 

 small spinules. The succeeding pairs of peraeopods are long and slender, the 

 fourth pair extending beyond the antennal scale. The dactylus is nearly one-third 

 the length of the propodus. 



End of telson (Fig. 24) with a sharp median point, longer than the outer but 

 shorter than the inner pair of terminal spines. 



Seven specimens, most of them very imperfect, are in the collection ; only one of 

 the large chelae is preserved. One specimen is a female carrying ova. The species 

 was dredged at a depth of 50 feet. 



Length of largest specimen ( $ ), 25 mm. 



Length of ovigerous female, 23 mm. 



Length of specimen figured ( <$ ), 18 mm. 



Length of second peraeopod of same, 11. 5 mm. 



The species appear to fall into the group Ettpalamoti as defined by Orlmann 

 (Zool. Jahrb., Abth. f. Syst. v. 1891, p. 696), in which the second peraeopods 

 are cylindrical, while the equality of the merus and carpus of these appendages and 

 the characters of the telson will bring it into proximity with such species as 

 P. scabriculus Heller and /'. endehetisis de Man. F. niloticus Roux, the only 

 species known from North America, is somewhat similar to the present form, but, 

 so far as can be judged from the more or less defective figures and descriptions of 

 Roux (Ann. Sc. Nat. xxviii. 1833, p. 73, pi. vii. f. 2) and Klunzinger (Zeitschr. 

 f. wiss. Zool. xvi. 1866, p. 357, pi. xx.), appears to present distinctive characters. 

 Both these authors figure the rostrum with a very convex upper edge. Klunzinger 



gives the number of serrations as •*, Roux figures — . According to the figures 



of both authors, however, not more than one tooth appears to be behind the orbit. 

 Both show the carpus of the 2nd peraeopod to be distinctly shorter than the merus, 

 and much more than half the length of the hand. Klunzinger's figure of the chela 

 shows it to be more slender, with the palm less inflated and the fingers longer than 

 in our species. 



Neither of the species can be depended on as throwing any light on the general 

 question of the origin of the Tanganyika fauna. The genus Palamon contains 



