130 OSTARIOPHYSI. 
2. Humeral process extending beyond middle of pectoral spine. 
Adipose fin ? the length of the fish; analofl2rays . . . . . . . «15. salvini. 
Adipose fin 3 the length of the fish; analofl5rays . . . . . . . . 16. polycaulus. 
III. Caudal fin slightly notched, nearly truncate. 
Maxillary barbel extending to middle of pectoral fin ; j atipose fin 3 the 
length of the fish . . . 17. rogersi. 
Maxillary barbel extending to ventral fin ; ‘adipose fin 2 2 the length of 
the fish 2. 2 1 1 we ee eee ee ee ee we 18, daticauda. 
1. Rhamdia parryi. 
Rhamdia parryi, Eigenm. Proc. Calif. Acad. Sci. (2) i. 1888, p. 180°; Jord. & Everm, Bull. U.S. 
Nat. Mus. xlvu. 1896, p. 153’. 
Depth of body 44 to 5 in the length, length of head 44 to 43. Breadth of head 1} in its length. Diameter 
of eye 5 in the length of head, 2 in the length of snout, 14 in the interorbital width. Lower jaw shorter 
than the upper; width of mouth 2% to 3 in the length of head (about 2 to 4 the width of head). 
Maxillary barbel extending to or beyond the dorsal fin. Head covered with smooth skin ; occipital 
process as broad as long, extending 4 of the distance from its base to the origin of dorsal. Dorsal 1 6; 
spine slender. Length of adipose fin 3 to 34 in the length of the fish. Anal 12-14. Pectoral spine 
slightly more than 4 the length of head. Lower caudal lobe rounded. Brownish ; a blackish lateral 
stripe. 
Hab. Mexico, Rio Zanalenco in Chiapas }. 
Apparently allied to R. motaqguensis. 
2. Rhamdia motaguensis. (Tab. XX. fig. 1.) 
Pimelodus motaguensis, Giinth. Cat. Fish. v. p. 127 (1864) *. 
Rhamdia motaguensis, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 151’. 
Depth of body 52 to 64 in the length, length of head 53 to 53. Breadth of head 1} to 13 in its length, 
length of snout 24 to 22, diameter of eye 5 to 6, interorbital width 3 to 33. Lower j jaw shorter than the 
upper; width of snout a the width of head. Maxillary barbel extending to middle of dorsal (adult) or 
nearly to adipose fin (yc oung). Head covered with smooth skin; occipital process extending 2 of the 
distance from its base to the origin of dorsal. 8 or 9 gill-rakers on the lower part of the anterior arch. 
Dorsal I 6; spine slender; first branched ray the longest. Length of adipose fin 34 in the length of the 
fish. Anal 18. Humeral process not extending to middle of pectoral spine, which is about 2 the length 
of the fin and 3 to 2 the length of head. Ventrals inserted behind the last dorsal ray, extending 3 to $ of 
the distance from their base to the origin of anal. Caudal deeply notched. Least depth of caudal 
peduncle 13 in the length of head and 14 to 2 in the distance from anal to base of caudal. _ Brownish ; 
dorsal dusky, with a pale band near the base. 
Hab. British Honpuras, Stann Creek (fobertson); GuateMALa, Rio Motagua! 
(Salvin). 
Here described from two specimens, the type, 210 mm. in total length, and one of 
130 mm., from Stann Creek. 
3. Rhamdia nicaraguensis, (Tab. XX. fig. 2.) 
Pimelodus nicaraguensis, Giinth. Cat. Fish. v. p. 125 (1864) ’. 
Rhamdia nicaraguensis, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 152%. 
