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. 



Bunoccpkalux hi/j>siiiriis Kuer, SB. Ak. Wieu, xvii, 1855, 98, pi. 1, 



iig. 1. (Eio Braiico.) 

 BunocephaUchthys hypsiurus Giinther, Catal. Fish. Brit. Mus. v, 



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



1889, 48. (Name only.) 

 Habitat: Kio 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. 



<CBunoce2^haliis Kner, SB. Ak. Wien, xvii, 1855 (sp). 



^Biinoceiihaliis Bleeker, Nederl. Tijdschr. Dierk. i, 

 1863 {verriicosiis). 



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 serra^ 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. 



b. Distance of dorsal from tip of snout 2-2^ 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. scahriccps 2. 



cc. Head dej^ressed, its depth about li in the distance between 

 tip of snout and base of pectoral; nuchal plate broad, its width 'iil 

 in its length; coracoid processes parallel. verrucosus 3. 



