1887.] BY MR. C. BUCKLEY IN EASTERN ECUADOR. 281 



The height of the body is considerably less than the length of the 

 head, and is one fifth of the total (without caudal) ; the length of 

 the head is contained about four times and one fourth in the total 

 (without caudal). Lower jaw obtuse, projecting beyond the upper ; 

 the inner borders of the mandibles closely approximate anteriorly, 

 diverging posteriorly, the part of the chin exposed between them 

 being ^-shaped, as in P. unitceniata \ The maxillary extends 

 beyond the anterior margin of the orbit. The diameter of the eye 

 is nearly half the width of the interorbital space, a little less than 

 the extent of the snout, and one fifth of the length of the head. 

 The origin of the dorsal fin is nearer to the root of the caudal than 

 to the end of the snout, and behind the vertical from the base of the 

 ventral. Adipose fin very small ; caudal forked, with its basal half 

 scaly. The length of the pectoral is two thirds of that of the head, 

 and exactly one half of its distance from the ventral. Ventral shorter 

 than pectoral. Pale brown above, yellowish inferiorly ; a black 

 lateral band becoming greyish and rather indistinct in the adult; 

 a black spot on the base of the anterior dorsal rays, another on the 

 root of the caudal fin. 



Total length 145 millim. 



Two adult specimens from Canelos, and three young from 

 Sarayacu. 



24. Tetragonopterus rutilus, Jen. 

 letragonopterus fasciatus, Gthr. 

 Canelos. 



25. Creagrutus muelleri, Gthr. 

 Canelos. 



26. Paragoniates alburnus, Stdr. 



Paragoniates alburnus, Steind. Sitzungsb. Ak. Wien, Ixxiv. i. 

 1876, p. 117, pi. viii. fig. 3. 

 Canelos. 



Leptagoniates, g. n. 



Body elongate, very strongly compressed. Dorsal fin short, 

 placed behind the middle of the length of the body, far behind the 

 ventrals ; anal very long, nearly two thirds the length of the body. 

 Cleft of the mouth narrow ; prsemaxillary, maxillary, and mandible 

 with a single series of tricuspid teeth. Gill-openings wide. Scales 

 moderate. Lateral line complete. 



The nearest ally of this new genus is Paragoniates, Steind., which 

 differs in the following points : — Cleft of the mouth wide ; anal 

 originating very slightly in advance of the dorsal ; lateral hue 

 interrupted. 



^ In P. eryfhrinoides, C. & V., the inner borders of the mandibles are widely 

 separated in front and nearly parallel. 



