126 MEMOIRS OF THE CARNEGIE MUSEUM 



aa. A. 7; distance from snout to dorsal considerably more than 3 in the length with caudal; width more 



than 3 in the length; general color dark chocolate amaurus. 



aaa. A. 8 or 9, rarely 7; distance from snout to dorsal more than 3 in the length with the caudal; width less 

 than 3 in the length; general appearance sand-like chamaizelus. 



8. Bunocephalus gronovii Bleeker. (Plate I, figs. 2-2a.) 

 Aspredo verrucosa Gronow, Cat. Fish, ed. Gray, 1854, 137 (not of Bloch). 

 Bunocephalus verrucosus Kner., SB. Akad. Wiss. Wien., XVIII, 1855, 96 (Barra do 



Rio Negro). 

 Bunocephalus gronovii Bleeker, Ichth. Arch. Ind. Prodr., I, 1858, 329 (based on 

 Gronow, Mus. Ichth., II, 1756, 5, No. 153, pi. 5, fig.3). — Gunther, Cata- 

 logue, V, 1864, 266 (Demerara). — Eigenmann and Eigenmann, Proc. Cal. 

 Acad. Sci., (2), II, 1889, 48; Occasional Papers Cal. Acad. Sci., I, 1890, 17 — 

 Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, 380. 

 The following description by Gunther is based on a specimen (figs. 2-2a), 102 

 mm. long collected by Hancock. The distance between the end of the snout and 

 the origin of the dorsal fin is one-third, or nearly one-third, of the total length 

 (with the caudal fin) ; the length of the head to the gill-opening is rather more than 

 one-seventh. Upper jaw but little prominent. The maxillary barbel extends to 

 the third fifth of the pectoral; the dorsal is inserted nearer to the end of the snout 

 than to the root of the caudal. Hind portion of the tail as high as broad. Brown 

 ish, clouded and spotted with darker. 



Head to gill-opening 5 in the length; greatest width 3.5; distance of dorsal 

 from tip of snout 2.25; caudal 4; D. 5; A. 6. 



9. Bunocephalus amaurus sp. nov. (Plate I, fig. 2.) 

 Bunocephalus amaurus Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 



1910, 380 (name only). 



Type, 69 mm. Konawaruk. (Carnegie Museum Catalog of Fishes No. 

 1555.) 



Cotype, 53 mm. Konawaruk. (I. U. Cat. No. 11973.) 



Head to gill-opening 5.66 in the length; greatest width 3.5; distance of dorsal 

 from tip of snout 2.33 in the length; caudal nearly 5. D. 5; A. 7; depth of 

 head 1.5 in distance from pectoral to tip of snout; length of coracoid process about 

 equal to the distance between their bases; anterior margin of coracoid with an 

 externally perceptible crest. Head verrucose but without knobs; nuchal crest 

 prominent, a notch between it and the knobbed dorsal plate. 



Maxillary barbels reaching pectoral; pectorals not quite to ventrals; humeral 



