106 bulletin: museum of comparative zoology. 



Occipital process very short, not reaching J the distance from its base to the 

 dorsal. Suborbital covering the entire cheek ; maxillary not much longer than 

 snout, 3.3 in head. 



Gill-rakers very short, \ diam. of eye, 6+10. 



Many specimens, about 65-87 mm. long. Goyaz. 



Bryconamericus peruanus ricae, sp. nov. 



The specimens from Costa Rica have the origin of the dorsal an orbital diame- 

 ter nearer snout than to base of middle caudal rays. Scales 7-39 or 40-6 ; D. 10 

 or 11 ; A. 28-31. Eye 3 in the head, much larger thau in B. peruanus of the 

 same size ; iuterorbital equal to eye. 



Three specimens, 84-95 mm. long. Chitaria, Costa Rica. 



Brycochandus, gen. nov. 

 This genus is a Creatochanes with an incomplete lateral line. 

 Type. — Brycochandus durbini, sp. nov. 



Brycochandus durbini, sp. nov. 1 



Head 4.2 ; depth 3.66-3.75 ; D. 11 ; A. 27 ; scales 6-39 to 40-4; lateral line 

 with pores on the first 30 scales ; eye 2.4 in the head, iuterorbital 2.5. 



Compressed slender ; mouth large, maxillary equal to length of eye. Maxillary 

 with two wide, 3-pointed teeth and about two minute, conical ones. 



A round, hyaline spot equal to the length of the middle caudal rays covering 

 the basal portion of the upper lobe. Caudal otherwise dark. A narrow, blackish 

 lateral stripe subtended by the broad silvery stripe. 



Two specimens, 38 and 39 mm. long. Rio Tapajos. 



Creatochanes gracilis, sp. nov. 



Head 4.5 ; depth 4.33 ; D. 11 ; A. II, 31£; scales 8-54-3|; (above ventrals), 

 5 above anal. Maxillary not reaching to end of second suborbital, its length 2.5 

 in the head. Premaxillary teeth | ; large mandibulary teeth 5 ; maxillary with- 

 out teeth. 



Greatest depth anterior to middle of body. 



Similar to C. melanurus. • 



One specimen, 75 mm. long. Rio Tapajos. 



Poptella, gen. nov. 



This genus differs from Gymnocorymbus by having a hidden predorsal spine. 

 It is most nearly related to Fowlerina. 



Type. — Tetragonopterus longipi?inis. Popta. 



1 For Miss Marion Lee Durbin. 



