1894.] NATURAL SCIENCES OF PHILADELPHIA. 403 



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



joint C. serratirostris. 



d,. Rostrum slightly bent upward, longer than the antenual 

 scale. Upper margin partially destitute of teeth. 

 e■^. The proximal teeth on the upper margin of rostrum 

 crowded, numerous. 

 /,. Carpal joint of the first pereiopoda a little shorter than 

 the hand. 

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



broad C. wycki (many). 



(/j. Carpal joint of the first pereiopoda only \l as long as 



broad C. nilotica (1). 



f^. Carpal joint of the first pereiopoda very much shorter 



than the hand C. grandirostris. 



63. The i^roximal 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,. Fingers of the first pereiopoda about as long as the palm. 



C. singhalensis (many). 



62. Fingers of the first pereiopoda much shorter than the palm. 

 C. brevirostris. 



1. Caridina typus Milne-Edwards, 1837.* 



Caridma typus Milne-Edwards, Hist. Nat. Crust., II, 1837, p. 363, pi. 2.5 bis, 



figs. 4, 5. 

 C. exilirost7-is Stimpson, Proceed. Acad. Xat. Sci., PWladelphia, 1860, p. 29. 

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

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



Beitr. Meeresfaun. Maurit. Seychell. 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. Sci., Philadelphia, 1893, p. 111. 

 C. typus M. E., Ortmann, Jenaische Denkschr., YIII, 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); Siam (Giebel); Flores, 



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



(Stimpson). 



2, Caridina americana Guerin, 1857. 



Guerin. Anim. Artie, in Eamon de la Sagra, Hist, de Pile 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 didribution: Cuba (Guerin, v. Martens); Dominica 

 (Pocock). 



* Caridina typhis Bate, Challenger Macr. 1888, p. 704, pi. 119, fig. 3, from 

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



