82 HAPLOMI. 



Dorsal 9 : origin above posterior part of anal, which ends below the middle of the dorsal. Anal 12; 

 origin equidistant from operculum and Ijase of caudal. Pectoral j| the length of head. Caudal sub- 

 truncate. Brownish; edges of scales darker; vertical tins with some small darker spots ; an ocellus on 

 the upper half of the base of the caudal fin. 



Hrd). Costa Rica, Juan Viiias [UiidenvoocU), San Jose {Biolleij). 



Two specimens, the type, 70 mm. in total length, and a much smaller example not 

 included in the description. 



2. Eivulus tenuis. 



Cynodonivhtliys tenuis, ilcek, Piibl. Columbian Mus., Zool. v. 190-1, p. 101, fig. 27'. 



Allied to R. qodinani, but with smaller scales and a smaller ej'e (diameter 3g- in the length of head m 

 a specimen of -10 mm.). 



Hab. Mexico, El Hnle in Oaxaca i. 



3. E-ivuliis godmani. (Tab. X. tig. 5.) 



Rivulus godrnuni, Pv,egan, Ann. Mag. Nat. Hist. (7) xix. 1907, p. 65. 



Depth of body 44 to 5 in the length, length of head 3^. Snout shorter than eye, the diameter of which is 3 

 in the length of head and a little less than the iut-erorbital width. 35 scahis in a longitudinal series. 

 Dorsal 8; origin above posterior part of aual, which ends below the middle of the dorsal. Anal 11 ; 

 origin equidistant from operculum and base of caudal. Pectoral j the length of head. Caudal sub- 

 truncate or rounded. Olivaceous, with a more or less distinct darker spot on each scale ; operculum 

 blackish ; vertical fins dusky, the caudal with a narrow light edge, and below with a blackish intra- 

 marginal stripe ; caudal ocellus sometimes present. 



Hah. Guatemala {Godman). 



Two specimens, 40 mm. in total length. 



4. Rivuliis isthmensis, 



Riuuliis htltmennis, Garmau, Mem. Mus. Comp. Zool. \ix. 1895, p. 140 '. 

 Hah. Costa Rica, Rio San Jose ^ 



4. CYPRINODON, Lacep., 1803. 



Cyprinodon, Jord. & Everm. liull. U.S. Nat. Mus. xlvii. 189G, p. 670. 



Oviparous. Mouth small, wilh short lateral cleft; rami of the lower jaw firmly uuited ; teeth incisor-like, 

 tricuspid, in a single series. 



About eight species comprise this genus, which ranges from the United States to 

 Brazil. In these the gill-openings are restricted from above, commencing only a little 

 above the level of the pectoral hns. The Old- World genus or subgenus Lehias ditfers 

 only in the greater freedom of the operculum. 



A few forms enter the sea and others are sometimes found in salt sprin^-s; they 

 are very variable and difficult to distinguish ; specimens without ventral fins are not 

 uncommon. 



