276 CALIFORNIA ACADEMY OF SCIENCES. 



217. Trachycorystes tr achy cor ystes. 



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



pi. 437, 1840 (Brazil?); Giiuther, Cat. Fish. Brit. Mns. v. 195, 



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; Eio Guapore; Eio Branco; EiO' 

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



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

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



Habitat: Guapore; Kios 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 l^ 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, 4| 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. 



