of Poiciliid Fishes. 503 



Head Wader than deep. Diameter of eye 4 

 111 the" length of head. 33 or 34 scales in a longitudinal 

 series. Dorsal 7-9 ; origin twice as distant from some part 

 of eye as from base of caudal. Anal 10-12, ending below 

 middle of dorsal. Pectoral | length of head, not extending 

 to pel vies, which reacli origin of anal. A few dark bars or 

 vertically expanded spots on the tail ; dorsal and caudal fins 

 usually spotted or barred. 

 Frencii Guiana. 



1-5 (co-types). 25-35 nun ; CarseTeune. Paris Mus. (Coll. Geay). 



17. Rivulus punctatus. 

 JRivulus punctatus, Bouleng. Boll. Mus. Torino, x. 1895, no. 196, p. 3. 



Depth of body 4j to 4| in the length, length of head 

 about 4. Head nearly as deep as broad. Diameter of eye 

 about 4 in length of head. 32 to 35 scales in a longitudinal 

 series. Dorsal 7-8 ; origin above posterior part of anal, 3 

 times as distant from eye as from base of caudal. Anal 

 12-13, ending below middle of dorsal. Pectoral | the length 

 of head or a little more, sometimes almost reaching pelvics, 

 which extend to the vent. A dark longitudinal band from 

 chin through eye, sometimes continued to the tail ; brownish 

 above, yellowish below the band ; small dark spots on sides, 

 mostly forming series running obliquely downward and 

 forward ; vertical fins with series of spots ; anal usually 

 dark-edged. 



La Plata. 



18. Rivulus istfimcnsis. 

 Rivulus isthmensis, Garman, Mem. Mus. Comp. Zool. xix. 1895, p. 140. 



Length of head 3J in length of fish. Head depressed. 

 Diameter of eye 3 in length of head. 32 scales in a longi- 

 tudinal series. Dorsal 9 ; origin over middle of anal, twice 

 as distant from head as from base of caudal. Anal 11, last 

 rav nearly as far back as that of dorsal. Olivaceous ; a dark 

 blotch at base of dorsal, another on back above or in front 

 of origin of anal. 



Kio San Jose, Costa Rica. 



