100 HAPLOMI. 



Hah. SouTHEitx Mexico, Otopa i, Motzorongo i, Venta Salada i, El liule i, Perez i, and 

 Cuicatlani in Vera Cruz, Oaxaca i, Tequesixtlan [Gadotv), San Geronimo - and 

 Tehuantepec in Oaxaca. 



Numerous examples, measuring up to 80 mm. in total length. 



3. Girardiims pleurospilus. 



Girardinus pleurospilus, Guut'u. Cat. Fish. vi. p. 355 (1866) \ and Trans. Zuol. Soc. vi. 1868, 



p. 486, t. 87. fig. 1 ^ 

 Helerandriaphurospilm, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 688". 



A series of from four to eight rounded dark spots, each about as large as the eye, along the middle of 

 the side. 



Hah. Guatemala, Lake of Duefias ^ -, Lake Nacasil {Salvin). 

 Numerous examples, measuring up to 60 mm. in total length. 



13. PCECILIA, Schneider, 1801. 



PcecUia, Giiutli. Cat. Fish. vi. p. 339 (1866); Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, 

 p. 690. 



Yiviparous. Anal fin, in the male, advanced and modified into an intromittent organ of moderate length. 

 Mouth small, transverse ; rami of lower jaw "weakljr connected ; minute teeth in bands, with an outer 

 series of more or less enlarged, curved, uuicuspid, movable teeth. Dorsal fin with 8 to 11 rays, higher 

 but not much longer in the males than in the females. Caudal rounded or subtruucate in both sesea. 



Hab. Mexico and Central America to Brazil; West Indies. 



P. elongata is known to enter the sea, and probably P. sphenops, which is abundant 

 in brackish water, does so also. 



Dr. Garman, in his monograph of the Cyprinodonts (Mem. Mus. Comp. Zool. xix. 

 1895), proposed a considerable reduction in the number of Mexican and Central- 

 American species of this genus. He placed P. couchiana, Girard, P. mexicana, 

 Steind., P. thermalis, Steind., P. petenensis, Giinth., P. dovii, Cfiinth., P. spilarus, 

 Giinth., and P. hntleri, Jord., in the synonymy of P. splienops, Cuv. & Val., and 

 P. elongata, Giinth., P. boucardi, Steind., and P. cldsoyensis, Giinth., in the synonymy 

 of P. gillii, Kner & Sleind. 



After examination of a large number of specimens I have reached the conclusion 

 that P. couchiana, P. fetenensh, P. spilurus, and P. elongata are very distinct and 

 easily definable species. The others enumerated appear to be merely forms of one 

 widely distributed and variable form, P. sphenopn. 



