SOUTH AMERICAN NEMATOGNATHI. 19 



This species is known only from the types. 



7, Bunocephalus knerii, 



Bunocephalus knerii Steindachner, Flussf. Siidam. iv, 9, pi. ii, fig. 



2, 1882 (Canelos); Boulanger, Proc. Zool. Soc. Lond. 1887, 278 



(Canelos); E. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 1889, 48 



(Cudajas; Tabatinga; Hyavary). 

 Habitat: Aniazons and tributaries from Cudajas westward to 



the Andes of Peru and Ecuador. 



Tail slender, terete. Depth at the occiput 1J in the 

 space between tip of snout and base of pectoral. 



Nuchal plate a thin, low crest; ridges of the head less 

 prominent than in any other species. 



Interorbital equals the snout plus the orbit. 



Maxillary barbel reaches base of pectoral; mental bar- 

 bel scarcely longer than the eye, postmental about twice 

 as long. 



Coracoid processes very short, equal to about half the 

 distance between them. 



Skin everywhere covered with warts, the lower sur- 

 face of the head least so. 



Distance of dorsal fin from tip of snout 2J in the 

 length. 



Tip of pectoral spine midway between tip of coracoid 

 process and origin of ventral fin. 



Sides dark gray with a series of light spots; head 

 lighter marked with blackish; about three dark gray 

 cross bands across the back; caudal blackish, mottled 

 and margined with light; other fins light, dotted or 

 blotched with gray. 



A. 7-8. 



Eight specimens .035 m. Cudajas; Tabatinga; Hya- 

 vary. Thayer Expedition. 



8, Bunocephalus aleuropsis, 



Bunocephalus aleuropsis Cope, Proc. Am. Philos. Soc. 1870, 568 

 (Pebas, Ecuador); E. & E. Proc. Cal. Acad. Sci. 2d Ser. ii, 

 1889, 48. 



Habitat: Ecuador. 



This species is known only from the type. 



