704 MB. W. T. OALMAN ON MACEUKOUS [May 16, 



EXPLANATION OP PLATE XXXVIII. 



Eig. 1. Limiiothelphusa maculafa, gen. et sp. noT. (p. 698). Adult male, general 

 view from above. X 2^ about. 



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



frame, epistome, antennules, and antennae. 



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



abdominal appendages and male genital papillae. 



4. External maxilliped. 



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

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

 7. Male abdomen, primitive dorsal view. 



Figures 2-7 considerably enlarged. 



'Reference Letters. 



a.g. G-enital aperture. cp. Epistome. 



f.h. Buccal fi-ame. 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 MACEUEA. 



Tribe C a r i d e a. 



Pamily Atyid^e. 



LiMNOOARiDiNA, gen. nov. 



Eostrum long, compressed, sei-rated. 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 perseopods. 



LlMNOOARIDINA TANGANYIKiE, sp. n. (Pktes XXXIX. & XL. 



figs. 1-2, 4-19). 



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

 and slender, gently recurved, varying from about 1^ to twice the 

 length of the carapace, and extending beyond the antennal scale 

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



1 Communicated by Prof. Gr. B. Howes, E.Z.S. 



