1906.] CRUSTACEA OF THE THIRD TANGANYIKA EXPEDITION. 199 



It is extremely difficult to determine exactly the number of gills 

 in species so small as those described below ; and the following 

 formula for C. cunningtoni is given with the reservation that 

 some minute vestiges of gills may have been overlooked. The 

 absence of the posterior pleurobranchia, however, as well as the 

 absence of an epipod from the penultimate legs, are characters 

 which it is comparatively easy to demonstrate and which seem to 

 justify the establishment of the new genus. 



In the case of C. cu7iningto'ni, the large and peculiar first pair 

 of chelfe and the unarmed dact3di of the third and fourth pairs of 

 legs are striking features. They are not shai'ed by C. minuta, but 

 owing to the small size of this species and the fact that only one 

 adult specimen was found it has not been possible to make a 

 complete examination of its characters, and it may yet prove to 

 belong to a distinct genus. 



Caridella cunningtoni, n. sp. (Plate XIII. figs. 45-52.) 



Bescrijytion. — Rostrum (Plate XIII. fig. 45) reaching nearly to 

 end of second segment of antennular peduncle, less than half 



length of carapace, slightly deflexed, teeth ^_^ — . Antennular 

 peduncle (Plate XIII. fig. 46) reaching to end of antennal scale, 

 second and third segments longer than broad, external spine of 

 first segment reaching to end of segment, distal spine reaching to 

 middle of succeeding segment. Distal edge of antennal scale 

 (Plate XIII. fig. 47) hardly projecting beyond external tooth. 

 Third maxilliped not extending to end of antennular peduncle. 

 First perfeojjods (Plate XIII. fig. 48) veiy stout, reaching to about 

 end of penultimate segment of third maxillipeds ; merus produced 

 as a blunt tooth above articulation of carpus ; carpus less than 

 twice as long as broad, distinctly excavated distally ; chela more 

 than one and a half times as long as carpus and rniich bi-oader, 

 less than two and a half times as long as broad ; fingers a little 

 shorter than the palm, gaping widely, a stout curved tooth at base 

 of immovable finger fitting into a notch at base of dactylus, apical 

 brushes scanty and short. Second per?eopods (Plate XIII. fig. 49) 

 slender, extending beyond tip of third maxillipeds ; carpus about 

 seven times as long as broad ; chela shorter than carpus, nearly 

 four times as long as broad, fingers one and a half times as long 



