136 OSTAEIOPHTSI. 



llah. GuATEjrALA, Eio San Geronimo ^ {Salvin). 



Plere described from the type, a specdmen measuring 135 mm. in total length. 



16. Rhamdia polycaulus. (Tab. XXll. fig. 3.) 



Pimeloduspohjccmlus, Giintli. Cat. Fish. v. p. 131 (18G4) \ 



Rhamdia 2:>olycauhis, Jord. & Evcrm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 153". 



Depth of bod)- 5-rr in the leugth, length of head 5^. Breadth of head \\ in its length, length of snout 24, 

 diameter of eye 5, interorbital width Si. Lower jaw shorter than the upper ; width of mouth 4 the 

 width of head. Maxillary barbel extending to posterior end of pectoral. Head covered with smooth 

 skin ; occipital process short, triangular, extending -i of the distance from its base to the origin of dorsal. 



6 gill-rakcrs on the lower part of anterior arch. Porsal I G ; spine slender, flu rounded, last ray cleft to 

 the base. Length of adipose fin 2j; in the length of the fish. Anal 15. Humeral process extending 

 nearly to end of pectoral spine, which is less than h the length of the fin and + the length of head. 

 Yentrals inserted behind the last dorsal ray, extending ~ of the distance from their base to the origin of 

 anal. Caudal moderately notched. Least depth of caudal peduncle 14 in the length of head or in the 

 distance from anal to base of caudal. Brownish. 



llah. Guatemala, Rio San Geronimo ^ [Salvin). 



Here described from the type, a specimen measuring 115 mm. in total length. 



17. Eliamdia rogersi. (Tab. XXlll. fig. 1.) 



Phnelodus rogersi, Regan, Ann. jMag. N. H. (7) xix. 1U07, p. 259'. 



Depth of body 6 in the length, length of head 5. Breadth of head li in its length, length of snout 3, 

 diameter of eye 6, interorbital width 3. Lower jaw shorter than the upper ; width of mouth 4 the 

 width of head. Maxillary barbel extending to middle of pectoral fin. Head covered with smooth skin ; 

 occipital process short, slender, extending about 4 of the distance from its base to the origin of dorsal. 



7 gill-rakers on the lower part of anterior arch. Dorsal I 6 ; spine slender, fin rounded. Length of 

 adipose fin about 4.} in the length of the fish. Anal 12-14, when laid back nearly reaching the vertical 

 from the end of adipose fin. Humeral process extending about to the middle of pectoral spine, which 

 has the inner edge serrated and measures nearly | the length of the fin or nearly | the length of head. 

 Ventrals originating behind the last ray of dorsal, extending g the distance from their base to the origin 

 of anal. Caudal slightlj- notched. Least depth of caudal peduncle about 1 j in the length of head or 

 l;l to 2 in the distance from anal to base of caudal. Brownish. 



Hal. Costa Rica, Irazu i [Bogcrs). 



Here described from the types, four specimens measuring up to 130 mm. in total 

 length. 



18. Rhamdia laticauda. 



Pimelodus laticaudus (Heck. MS.), Kuer, Sitzungsb. Ak. Wien^ xxvi. 1857, p. 420' ; Giintli. Cat. 



Fish. V. p. 127 (1864) \ 

 Rhamdia laticauda, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 152 \ 

 Evidently allied to the preceding, dificring at least in llie longer barbels and the longer adipose fin. 



IM. Mexico 1. 



Total length about 220 mm. 



