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Show 1906.] CRUSTACEA OF THE THIRD TANGANYIKA EXPEDITION. 193 than twice as long as the carpus, 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 setae regularly arranged; each seta has a double series of rather widely-spaced barbs. Last three pairs of peraeopods not differing greatly in length, third pair not reaching tip of third maxillipeds; dactylus of third and fourth pairs (Plate X L fig. 6) more than half the length of propodus, with 14 spines; that of the fifth pair (Plate X L fig. 7) nearly two-thirds of length of propodus, with 26 spines. Telson (Plate X L fig. 8) three-fifths of length of sixth abdominal somite. Outer plate of uropods longer than inner. Total length, 2 , 13*8 m m . Eggs '3 X '18 m m. Remarks.-This species is distinguished from all the Atyida? hitherto described by the remarkable and beautiful armature of its chelae. The setae with which the fingers are furnished, instead of forming apical tufts as in other Atyidae, 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 chelae 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 efficient 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 shows no important differences from the other members of the genus. Occurrence.-Mbete, l.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 X L figs. 9-14.) Description.-Body very slender; sixth somite of abdomen as long as the carapace, three times as long as deep. Rostrum (Plate X L 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 preceding segment. First peraeopods (Plate X L 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 X L 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 |