SOUTH AMERICAN NEMATOGNATHI. 85 



Arius dieperinki Bleeker, Silures de Suriuame 50, pis. x, aud xii, 



fig. 3, 1864 (Surinam). 

 Habitat: Marauliao and northward. 



This example differs from those described 

 above, in having the sides of the spines 

 striate, the fontanel broadly rounded be- 

 hind, the intermaxillary band of teeth 6 

 times as wide as deep, the palatine patches 1| 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 stidostlichen Brasilines iii, 86, pi. xi (Rio Doce). 



Tachisurus grandocuUs Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 

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



Habitat: Eio 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) I3-II 

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

 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 li 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, li in snout, 4^-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 r ^ 



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

 no teeth on the vomer. j^ v> 



