On Two new Siluroid Fishes from Brazil. 477 



LVIII. — Descriptions of Two neio Siluroid Fishes from 

 Brazil. By G. A. Boulenger, F.R.S. 



Brachyplaty stoma platynema. 



Vomerine teeth forming a very broad band, broader than the 

 band in the upper jaw, angularly notched behind ; another 

 notch between it and the patch of palatine teeth. Head 

 extremely depressed, twice as long as deep, 3|- times in total 

 length. Snout spatulate, rounded, projecting a little beyond 

 the mandible ; eye extremely small, in the posterior half of 

 the head, its diameter 4 times in interorbital width; occipital 

 process short, widely separated from the dorsal fin ; upper 

 surface of head covered with thin reticulate skin ; fontanelle 

 very small. Maxillary and mental barbels much flattened, 

 band-like, the former reaching extremity of ventral, the 

 anterior mentals nearly reaching extremity of pectoral, the 

 posterior mental hinder third of ventral. Branchiostegal 

 rays 12. Dorsal I 6, first ray ^ length of head; adipose fin 

 nearly three times as long as deep, f its distance from the 

 rayed dorsal. Anal IV 12, falciform, first branched ray 2\ 

 as long as last. Pectoral § length of head, spine feebly 

 serrated. Ventral as long as pectoral, widely separated from 

 anal. Caudal deeply forked, the lobes produced into very 

 long filaments. Caudal peduncle 3 times as long as deep. 

 Dark brown above, lighter beneath. 



Total length to middle caudal rays 430 millim. ; upper 

 caudal lobe with filament 250. 



A single specimen from Pard, ; presented to the British 

 Museum by Dr. E. A. Goeldi, Director of the Para Museum. 



This species is nearest allied to the recently described 

 Brachyplatystoma juruense, Blgr.*, from which it is distin- 

 guished by the broader band of teeth on the palate, the longer 

 snout, and the band-like barbels. From B. Vaillanti, 0. & V., 

 it differs in the above characters and in the smaller eye, the 

 shorter barbels, and the wider separation between the occipital 

 process and the dorsal fin. 



LEPTODOKAS, gen. nov. 

 Distinguished from Oxydoras, Kner, by the longer body 



* The name Platystoma, Ag., being preoccupied, baa been replaced by 

 that of Braehyjrfatystoma, Eigenm. 



Ann. & Mag. N. Hist. Ser. 7. Vol. ii. 33 



