1906.] CRUSTACEA OF THE THIRD TANGANYIKA EXPEDITION. 193 



than twice as long as the carious, palmar portion about one-fifth 

 of length of fingers. Fingers of both chelae slightly spoon-shaped, 

 bearing along the whole length of their opposed edges on the 

 outer and inner sides a single row of very long flexible set^e 

 regularly arranged ; each seta has a double series of leather 

 widely-spaced barbs. Last three pairs of pereeopods not differing 

 greatly in length, third pair not reaching tip of third maxillipeds ; 

 dactyl us of third and fourth pairs (Plate XI. fig. 6) more than 

 half the length of propodus, with 14 spines ; that of the fifth 

 pair (Plate XI. fig. 7) nearly two-thirds of length of propodus, 

 with 26 spines. Telson (Plate XI. fig. 8) three-fifths of length 

 of sixth abdominal somite. Outer plate of lu^opods longer than 

 inner. 



Total length, $ , 13-8 mm. Eggs -3 X '18 mm. 



Remarks. — This species is distinguished from all the Atyidse 

 hitherto described by the remarkable and beautiful armature of 

 its chela3. The sette with which the fingers are furnished, instead 

 of forming apical tufts as in other Atyidse, diverge from the 

 outer and inner edges of each finger. As far as can be seen in 

 the preserved specimens, these setae entirely prevent the fingers 

 from being brought together, so that the chela? cannot be used 

 for seizing objects in the ordinary way. On the other hand, each 

 chela forms a kind of double casting-net, no doubt very efiicient 

 in the capture of minute living prey. The great length of the 

 dactylus of the posterior legs is also a characteristic feature. In 

 the structure of the mouth-parts and in the branchial formula 

 the species shoAvs no important differences from the other members 

 of the genus. 



Occurrence. — Mbete, 1.x. 04. "Taken in shrimp-net, shore- 

 wading." Among 17 specimens there are only three females, one 

 of which carries eggs. 



LiMNOCARIDINA PARVULA, n. sp. (Plate XI. figs. 9-14.) 

 Description. — Body very slender ; sixth somite of abdomen as 

 long as the carapace, three times as long as deep. Rostrum 

 (Plate XI. fig. 9) very short, less than half as long as first 

 segment of antennular peduncle, expanded horizontally at the 

 base ; teeth " ^ " . Antero-lateral spine of carapace set more 

 than twice its own length from front edge. Antennular peduncle 

 reaching well beyond external tooth of antennal scale. Distal 

 edge of scale projecting beyond external tooth. Third maxilliped 

 extending to end of first segment of antennular peduncle, exopod 

 longer than ischium, terminal segment shorter than j)receding 

 segment. First perteopods (Plate XI. fig. 10) reaching to end 

 of penultimate segment of third maxillipeds, breadth of carpus 

 less than two-thirds of its length ; chela about three times as long- 

 as carpus, palmar portion about one-seventh of length of fingers. 

 Second peraeopods (Plate XI. fig. 11) reaching a little beyond 

 first, breadth of carpus little more than half its length, chela 

 two and a half times as long as carpus, palmar portion about 



