SOUTH AMERICAN NEMATOGNATHI. 85 



Arius dieperinki Bleeker, Silures de Suriname 50, pis. x, and xii, 



fig. 3, 1864 (Surinam). 

 Habitat: Maranhao and northward. 



This example differs from those described ,^~~ \' 

 above, in having the sides of the spines ^ j , -^ 



striate, the fontanel broadly rounded be- \ / \^ ] 



hind, the intermaxillary band of teeth 6 30 



times as wide as deep, the palatine patches 1J diame- 

 ters of the eye in width and length. 



No. 7694, one specimen .27 m. Maranhao. 



56, Tachisurus grandoculis. 



Arius grandoculis Steindachner, SB. Ak. Wien, Ixxiv, 1876. Stiss- 

 wasserfische siidostlichen Brasilines iii, 86, pi. xi (Bio Doce). 



Tachisurus grandoculis Eigenm. & Eigenrn. Proc. Cal. Acad. 2d Ser. 

 vol. i, 1888, 145 (Kio Doce). 



Habitat: Rio Doce. 



Form compressed, the width about a third less than 

 the depth, the nose rather pointed. Head a little higher 

 than broad, its height (at base of occipital process) 1J-1| 

 in its length, its width 1J, at the angle of the mouth 2J. 

 Granulations of the head rather fine, extending usually, 

 to above the anterior part of the orbit, forming striae. 

 Occipital process long, its width, at base, about 1J in its 

 length; at tip nearly 3; granular, its ridge somewhat 

 blunt. Fontanel long, its center nearly over the middle 

 of the eye or a little in front, continued backward as a 

 groove. 



Eye very large, 1J in snout, 4J-5 in head, 1^ in inter- 

 orbital, about lf-2 in interocular. 



Maxillary barbels reaching past the middle of the 

 pectoral, the mentals past the gill-opening and the post- 

 mentals beyond base of pectoral fin. All the barbels 

 shorter in larger specimens. 



Snout decurved, projecting beyond the lower jaw, the 



mouth wholly inferior. Teeth all villiform, on ^ ^. 



the palate in two small, widely separated patches; ^~^^ 

 no teeth on the vomer. , N> 



