276 CALIFORNIA ACADEMY OP SCIENCES. 



217, Trachycorystes trachycorystes, 



Auchenipterus trachycorystes Cuv. & Val. Hist. Nat. Poiss. xv, 214,. 



pi. 437, 1840 (Brazil?); Giiuther, Cat. Fish. Brit. Mus. v. 1<J,">, 



1864 (copied). 

 Trachycorystes trachycorystes Eigenm. & Eigenm. Proc. Cal. Acad. 



2d Ser. i, 154, 1888 (name only). 

 Trachycorystes typus Bleeker, Nederl. Tijdschr. Dierkunde, i, 88, 



1863 (name only). 

 Habitat: ? 



218, Trachycorystes ceratophysus, 



Auchenipterus ceratophysus Kner, SB. Ak. Wien, xxvi, 427, pi. 

 vii, fig. 23, 1857 (Matogrosso; Rio Guapore; Rio Branco; Rio 

 Negro); Giinther, Cat. Fish. Brit. Mus. v, 196, 1864 (copied). 



Trachycorystes ceratophysus Eigenm. & Eigenm. Proc. Cal. Acad. 

 2d Ser.i, 154, 1888 (name only). 



Habitat: Guapore; Rios Negro and Branco. 



This species is known only from the types. 



219, Trachycorystes porosus. 



Trachycorystes porosus Eigenm. & Eigenm. Proc. Cal. Acad. 2d. Ser. 



i, 154, 1888 (Brazil). 

 Habitat: Brazil. 



Short and robust, little compressed; width of the head 

 about equal to its length, its depth 1J in its length. 

 Bones of the head coarsely granular. Fontanel oval. 

 Snout and sides of the head with conspicuous pores. 

 Three grooves on the occipital bone form a ^-shaped fig- 

 ure, and are studded with pores; other pores on top of 

 the head. 



Eye circular, 2 in the snout, 7 in the head, 4J in the 

 interocular. 



Maxillary and postmental barbels extending a little 

 beyond base of pectoral; mental barbels extending be- 

 yond insertion of postmentals, measuring If in the 

 length of the head. 



Lower jaw projecting; teeth fine, the intermaxillary 

 band about 8 times as wide as deep. 



Humeral process extending obliquely upwards, strongly 

 granular, its lower margin serrate; reaching a little be- 

 yond middle of pectoral spine. 



