ElGENMANN : THE EXPEDITION TO BRITISH GUIANA. 31 



Cotypes, 2 specimens, 27 mm. Warraputa. (C. M. Cat. No. 

 1068; I. U. Cat. No. 11753.) 



Cotypes, 3 specimens, 25 to about 38 mm. Tumatumari. (C. M. 

 Cat. No. 1069; I. U. Cat. No. n 754.) 



Head 4; depth 4-^- ; D. 10; A. 11 ; scales 6-36-2.5; eye 2.6; 

 interorbital 3.5. 



Elongate, heaviest above middle of pectoral, the width about one- 

 half the depth ; preventral area broadly rounded, postventral rounded ; 

 predorsal area broad, with an obscure keel ; a median series of about 

 ten scales. 



Occipital process very short, about one-seventh of the distance of its 

 base from the dorsal ; skull smooth, but slightly convex ; frontal fon- 

 tanel triangular, nearly as long as the parietal ; mouth rounded, pro- 

 jecting beyond the lower jaw ; cheeks long and low, the second sub- 

 orbital about twice as long as broad, its convex margin leaving a con- 

 siderable naked area except at a point of contact with the lower limb 

 of the operculum. 



Maxillary-premaxillary border forming a simple, concave curve; 

 horizontal extent of the premaxillary about equal to the length of the 

 maxillary, which is equal to half the length of the eye. Nine teeth in 

 each premaxillary, those in the maxillary similar and continuous with 

 the last of the premaxillary teeth ; outer teeth of the premaxillary con- 

 ical, inner tricuspid; about seven tricuspid teeth in the dentary, of 

 which the first three are large, the rest minute ; tips of all the teeth, 

 except those of the maxillary and those of the sides of the lower jaw, 

 brown. Lower jaw short, less than length of eye. 



Gillrakers 4+10. 



Scales very thin ; anal sheath none, caudal lobes naked, except for 

 a few large scales on the lower lobe, axillary scale well developed. 



Origin of dorsal in advance of the middle ; origin of anal in advance 

 of that of the dorsal ; origin of anal behind the last ray of the dorsal ; 

 adipose slightly behind base of last dorsal ray ; ventrals not reaching 

 anal ; pectorals not nearly to ventrals. 



Straw-colored, a bright silvery band ; first suborbital, cheeks, and 

 opercle behind eye, snout, and upper part of head dotted. A contin- 

 uous curved band crossing third and fourth scale of the lateral line ; 

 scales of the back with one to several series of dots on the margin ; 

 silvery lateral band underlaid with a dotted stripe, a small caudal spot 



