EHAMDIA. 135 



13. Rhamdia brachycephala. (Tab. XXII. fig. 2.) 



Pimelodus brachycephalus, Regau, Ann. Mag. N. H. (7) xix. 1907, p. 2.58 \ 



Depth of body 5| to Gi in the length, length of head 5.} to 5i. Breadth of head li in its length, length of snout 

 2| to 3, diameter of eye 5 to 6, interorhital width 3 to 3J. Lower jaw a little shorter than the upper ; 

 width of mouth 4 to f the width of head, ilaxillary barbel extending to tlie basal part of pectoral. 

 Head covered with smooth skin ; occipital process slender, extending about 1 of the distance from its 

 base to the origin of dorsal. 6 to 8 gill-rakers on the lower part of the anterior arch. Dorsal I G, the 

 spines slender, the fin rounded. Length of adipose fin ?j\ to 3^ in the length of the fish. Anal 12-13, 

 when laid back sometimes reaching the vertical from end of adipose fin. Pectoral spine with serrated 

 inner edge, about i the length of the fin and -| the length of head ; humeral process extending to or 

 beyond the middle of the spine. Ventrals originating behind the dorsal, extending h to 4 the distance 

 from their base to the origin of anal. Caudal moderately notched, the lower lobe rounded and rather 

 shorter than the upper. Least depth of caudal peduncle )j or more than ^ the length of head, V4 to \i 

 in the distance from anal to base of caudal. Brownish. 



Hah. Guatemala, Eio Nacasil ^ (Salvin). 



Here described from tiie types, six specimens, measuring up to 190 mm. in total 

 length. 



14. Ehamdia underwoodi, sp. n. (Tab. XXIII. fig. 4.) 



Depth of body 5^ to G in the length, length of head 4f to 5. Breadth of head li to 1^ in its length, length 

 of snout 2-| to 2^, diameter of eye G to 7, interorhital width 3. Lower jaw scarcely shorter than the 

 upper ; width of mouth 4 to | tho width of head. Maxillary barbel extending to posterior end of pectoral 

 fin. Head covered with smooth skin ; occipital process extending i or Jr of the distance from its base to 

 the origin of dorsal. 7 or 8 gill-rakers on the lower part of the anterior arch. Dorsal I 6 (exceptionally 

 I 7) ; spine slender, fin rounded. Length of adipose fin 3j to 4| in the length of the fish. Anal 11-12., 

 Humeral process short, not extending to middle of pectoral spine, which has the inner edge serrated 

 and measures about 5 the length of the fin and j to 'i the length of the head. Ventrals inserted behind 

 the last ray of the dorsal, extending | to - of the distance from their base to the origin of anal. Caudal 

 moderately notched. Least depth of caudal peduncle 1^ to 2 in the length of head and 1:1 to 1^ in the 

 distance from anal to base of caudal. Blackish grey. 



Ilab. Costa Eica, Juan Vifias [Undenoood). 



Four specimens, the largest 100 mm. in total length. 



15. Rhamdia salvini. (Tab. XXIII. fig. 2.) 



Pimelodus salvini, Giintli. Cat. Fisli. v. p. 130 (1864) \ 



Rhamdia salvini, Jord. & Evenn. Bull. U.S. Nat. Mus. xlvii. 1896, p. 152'. 



Depth of body 6^ in the length, length of head 5?r. Breadth of head 11 in its length, length of snout 2^, 

 diameter of eye 6, interorhital width 3^. Jaws nearly equal anteriorly ; width of mouth f the width of 

 head. Maxillary barbel extending a little beyond middle of pectoral. Head covered with smooth skin ; 

 occipital process short, triangular, extending \ of the distance from its base to the origin of dorsal. 

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

 adipose fin 3| in the length of the fish. Anal 12. Humeral process extending beyond the middle of the 

 pectoral spine, which is about h the length of the fin and 5 the length of head. Ventrals inserted behind 

 the last dorsal ray, extending '4; of the distance from their base to the origin of anal. Caudal moderately 

 notched. Least depth of caudal peduncle Ij in the length of head and 2 in the distance from anal to 

 base of caudal. Brownish. 



