704 ME. w. T. OALMAN om MACEUEOUs [May 16, 



EXPLA]!fATION OF PLATE XXXVIII. 



Pig. 1. Limnothelphiisa maculata, gen. et sp. nov. (p. 698). Adult male, general 

 view from above. X 2 ^^ about. 



2. Ventral view of the anterior portion, to show the relations of buccal 



frame, epistome, antemiules, and antennae. 



3. Ventral view of posterior portion of thorax, abdomen removed, Bhowlng 



abdominal appendages and male genital papiUse. 



4. External maxilliped. 



5. Dactylus of walking-leg, to show the nature of the spinules. 

 li. Terminal portion of cheliped, showing nature of dentation. 

 7. Male abdomen, primitive dorsal view. 



Figures 2-7 considerably enlarged. 



Eeference Letters. 



a.g. Genital aperture. ep. Epistome. 



f.b. Buccal frame. t.so. Sub-ocular tooth. 



3. On two Species of Macrurous Crustaceans from Lake 

 Tanganyika. By W. T, Calman, B.Sc, University 

 College, Dundee.^ 



[Eeceived April 29, 1899.] 



(Plates XXXIX. & XL.) 



The Crustaceans collected in Lake Tanganyika by Mr. J. E. S. 

 Moore and placed in my hands for examination comprise specimens 

 of two species of Prawns, one forming the type of a new genus 

 allied to Caridina, the other being a probably new species of 

 Palcemon. 



Sub-order MACErEA. 



Tribe C a r i d e a. 



EamUy Atyid^e. 



LiinfOCAEiDiNA, gen. nov. 



Eostrum long, compressed, serrated. Carapace with a hepatic 

 spine. Pereeopods without exopods. Carpal joint of first pair 

 slightly excavated distally, that of second pair not excavated. No 

 epipods on any of the thoracic appendages. Grills four in number 

 on each side, corresponding to the first four pairs of peraeopods. 



LiMNOCAEiDUfA TAifGAKYiK^, sp. n. (Plates XXXIX. & XL. 

 figs. 1-2, 4-19). 



Descripion. — The rostrum (PL XXXIX. figs. 1-2) is very long 

 and slender, gently recurved, varying from about I3 to twice the 

 length of the carapace, and extending beyond the antennal scale 

 by g to nearly g its length. There are from 12-15 teeth on its 



1 CommuDicated by Prof. G. B. Howes, F.Z.S. 



