1894.] NATURAL, SCIENCES OF PHILADELPHIA. 403 



/ 2 . Spine at the base of the antennulse longer than the first 



joint C. serratirostris. 



d 2 . Rostrum slightly bent upward, longer than the antennal 

 scale. Upper margin partially destitute of teeth. 

 e x . The proximal teeth on the upper margin of rostrum 

 crowded, numerous. 

 f 1 . Carpal joint of the first pereiopoda a little shorter than 

 the hand. 

 g x . Carpal joint of the first pereiopoda 2-2 J as long as 



broad C. wycM (many). 



g 2 . Carpal joint of the first pereiopoda only 1J as long as 



broad C. nilotica (1). 



/ 2 . Carpal joint of the first pereiopoda very much shorter 



than the hand C. grandirostris. 



e 2 . The proximal teeth on the upper margin of rostrum re- 

 mote, not numerous C. gracilirostris. 



a 2 . Rostrum very short, not serrated. Anterior margin of the carapace 

 without an antennal spine. 

 6 X . Fingers of the first pereiopoda about as long as the palm. 



C. singhalensis (many) . 



6 2 . Fingers of the first pereiopoda much shorter than the palm. 

 C. brevirostris. 



1. Caridina typus Milne-Edwards, 1837. 8 



Caridina typus Milne-Edwards, Hist. Nat. Crust., II, 1837, p. 363, pi. 25 bis, 

 figs. 4, 5. 



C. exilirostris Stimpson, Proceed. Acad. Nat. Sei., Philadelphia, 1860, p. 29. 



C. siamensis Giebel, Zeitscbr. f. d. ges. Naturw., 21, 1863, p. 329. 



C. typus M. E., Miers, Philosoph. Trans. London. 168, 1879, p. 492. Eichters, 

 Beitr. Meeresfaun. Maurit. Seycbell. Decap., 1880, p. 162, pi. 17, fig. 23. 



C. typus M. E., de Man, in Weber, Zoolog. Ergebn. Eeis. Niederl. Ost- 

 Indien, II, 1892, p. 367, pi. 21, fig. 22. 



C. typus M. E., de Man, Not. Leyd. Mus., 15, 1893, p. 300. 



C. typus M. E., Sharp, Proceed. Acad. Nat. Sei., Philadelphia, 1893, p. 111. 



C. typus M. E., Ortmann, Jenaische Denkschr., VIII, 1894, p. 8. 



Geographical distribution'. Fresh-water of the Islands of the 

 Indian Ocean and of Indo- Malaysia. — Mauritius (Richters, Sharp); 

 Rodriguez (Miers); Seychelles (Richters); Siani (Giebel); Flores, 

 Timor, Saleyer, Celebes (de Man); Amboina (Ortmann); Loo-Choo 

 (Stimpson). 



2. Caridina americana Guérin, 1857. 



Guérin, Anim. Artie, in Ramon de la Sagra, Hist, de Hie de Cuba, 1857, p. 



52, pi. 2, fig. 13. 

 v. Martens, Arch. f. Naturg., 38, 1, 1872, p. 135. 

 Pocock, Ann. Mag. Nat. Hist. (6), III, 1889, p. 16, pi. 2, fig. 4. 



Geographical distribution: Cuba (Guérin, v. Martens); Dominica 



(Pocock). 



8 Caridina typus Bate, Challenger Macr. 1888, p. 704, pi. 119, fig. 3, from 

 San Jago, Cape Verde Isl. is probably a different species. 



