SOUTH AMERICAN NEMATOGNATHI. 179 



Opercle as wide as eye. Humeral process very angu- 

 lar rhomboidal, wider than in II. 



Adipose dorsal 1| in head. Dorsal spine 1 in head; 

 pectoral spine 1| in head; ventral fin 1| in head. 



Plain dusky, all the fins dusky; a dark spot at base of 

 dorsal spine; sometimes with a light streak along the 

 lateral line. 



The specimens in the museum are from Avary, Para; 

 Iga; San Goncallo; Jutahy; Rio Puty. 



The longest specimen measures .25 m. 



124e. Dorsal spine longer than head; humeral pro- 

 cess triangular. 



Maxillary barbel extending beyond base of caudal; 

 mental beyond base of ventral; postmental to near dp of 

 pectoral. Eye 2 in snout, 3-4i in head. Distance be- 

 tween anterior and posterior nares 2 in eye. Width 

 of intermaxillary band of teeth about 6 in its length. 

 Opercle about equal to the length of the eye. Caudal 

 lobes pointed, 3 longer than head. Adipose dorsal about 

 5 in the length. Dorsal spine 3 longer than head; pec- 

 toral spine about as long as the head. Ventral fins little 

 shorter than head. 



Color brownish, white below. 



This variety representing the riiiacroneina of Bleeker is 

 represented by several specimens from the Amazon. 



From the descriptions here given it wdll be seen that 

 not all the varieties so far described are represented; 

 also that some not yet described are in the collection. 

 We have not thought it best to name the old or the new 

 varieties. In order to settle the boundaries of each 

 variety, one should have an unlimited supply of s^^eci- 

 mens of all the varieties; until such a collection is made 

 it is useless to name them as there would assuredly be a 

 shifting of names, and the confusion is already great 

 enoush. 



