SOUTH AMERICAN NEMATOGNATHI. 239 



177, Doras weddellii, 



Doras weddellii Castelnau, Anim. Amer Sud. 48, pi. xvii, fig. 1, 

 1855 (Chiquitos); Giiuther, Cat. Fish. Brit. Mus. v, 203, 1864 

 (Santarem); Vaillant, Bull. Soc.Philom, Ser. 7, iv, 154, 1880 (Cal- 

 deron); Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 163, 1888 

 (Fonteboa Teffe; Serpa; Porto do Moz; Silva, L. Saraca). 



Doras grypus Cope, Proc. Acad. Nat. Sci. Philad. 1872, 270, pi. xv, 

 fig. 1-la (Ambyiacu Kiver). 



Habitat: Amazon and its tributaries, most abundant westward. 



The original figure and description of weddellii are very 

 poor. Our specimens are lighter colored than the figure 

 by Prof. Cope; the whitish blotches below the lateral 

 line being continued up and meeting on the back. 



Depth below the dorsal spine less than the width, ta- 

 pering backward. Head short, its width equal to its 

 length, its depth 1J in its length. Bones of the head 

 rather finely granular, with large, depressed smooth 

 areas. Dorsal plate with a downward projecting branch. 

 Fontanel elliptical, as long as the eye, its posterior mar- 

 gin extending farther back than the eye, becoming sur- 

 rounded with granular bones in older specimens. Nasal 

 and suborbital bones covered with skin, the former be- 

 coming exposed and granular in the old. 



Interorbital area flat. Eye small, lf-1-J in the snout, 

 about 7 in the head; 2J in the interorbital. 



Maxillary barbels extending beyond base of pectorals, 

 postmeiitals about as long as the maxillaries, mental 

 barbels somewhat shorter. Snout broad, its width at 

 the rictus about 2 in the head: in the young its upper 

 surface is covered with skin, two series of conspicuous 

 pores; in the old some of the bones become more or less 

 granular and exposed, the pores less distinct. Mouth 

 terminal; jaws equal; teeth in very shallow bands. 



Gill-opening continued forward below to a point mid- 

 way between posterior margin of eye and the upper angle 

 of the preopercle. 



First three lateral scutes higher than the rest, touch- 



