14 CALIFORNIA ACADEMY OF SCIENCES. 



Tail compressed, higher than broad; head lower than 

 the tail; dorsal surface of the head with osseous pro- 

 tuberances. Outer surface of pectoral spine smooth, 

 caudal rounded. 



1, Bunocephalichthys hypsiurus, 



Bunocephalus hypsiurus Kner, SB. Ak. Wien, xvii, 1855, 98, pi. 1, 



fig. 1. (Eio Branco.) 

 Bunocephalichthys hyftsiurus Giinther, Catal. Fish. Brit. Mus. v, 



267, 1864 (copied); E. & E. Proc. Cal. Acad. Sci., 2d Ser. ii, 



1889, 48. (Name only.) 

 Habitat: Eio Branco. 



Protuberances of the head in two curved series; tail 

 with undulating ridge above and below. Light yel- 

 lowish spots along the lateral line; anal white edged. 

 (Kner.) 



II. BUNOCEPHALUS. 



<Bunocephalus Kner, SB. Ak. Wien, xvii, 1855 (sp). 



= Bunocephalus Bleeker, Nederl. Tijdschr. Dierk. i, 

 1863 (verrucosus). 



Type: Platystacus verrucosus Bloch. 



Dorsal well developed, of five rays, the last of which 

 is adnate; tail terete or quadrangular. Upper surface 

 of the head with osseous protuberances and ridges. 

 Pectoral spine with recurved serrye on both margins, 

 largest near the tip. Barbels 6, the maxillary barbels 

 not extending beyond middle of pectoral. Eye minute. 



Habitat: Amazon from Serpa to the mountains of 

 Ecuador and Peru; Demarara. 



ANALYSIS OF THE SPECIES OF BUNOCEPHALUS. 



a. A. 6. 



6. Distance of dorsal from tip of snout 2-2J in the length. 



c. Head high, its depth at occiput equal to the distance between tip 

 of snout and base of pectoral; nuchal plate narrow with two high 

 knobs; bony protuberances of the head greatly developed; coracoid 

 processes converging backward. scabric<'j* '2. 



cc. Head depressed, its depth about 1J in the distance between 

 tip of snout and base of pectoral; nuchal plate broad, its width 3J 

 in its length; coracoid processes parallel. verrucosus 3. 



