284 Field Museum of Natural History — Zoology, Vol. X. 



Color silvery; sides with a plumbeous lateral band, ending in a 

 large, black, caudal spot, which is slightly longer than deep and extended 

 only slightly on base of caudal. An ill-defined shoulder spot present. 



This species is represented in the Panama collection by numerous 

 specimens, ranging in length from 45 to 90 mm. It occurs on both 

 slopes of Panama, and is always found in company with Astyanax 

 mberrimus, but much less abundant, except in the Rio Tuyra Basin 

 where it outnumbers the latter. 



Habitat: Both slopes of Panama. 



32. Bryconamericus cascajalensis sp. nov. 



Type No. 8946, F. M. N. H.; length 92 mm.; Rio Cascajal, Porto 

 Bello, Panama. 



Head 3.8 to 4; depth 2.6 to 2.95; D. 10 or 11; A. 26 to 29; scales 40 

 to 48. 



Body moderately elongate, compressed; the back elevated; head 

 small; snout conical, 3.4 to 4.25 in head; eye 2,6 to 3; interorbital 2.6 to 

 3; mouth small; jaws subequal; maxillary reaching to or slightly past 

 anterior margin of pupil, a little longer than snout; premaxillary teeth 

 in 2 series, the outer series irregular, with 10 teeth, the inner series 

 regular, with 8 teeth; maxillary with 2 small teeth near its junctiu-e with 

 the premaxillary; lower jaw with 8 strong teeth anteriorly and abrubtly 

 smaller ones at sides; gill-rakers short, about 12 on lower limb of first 

 arch; lateral line complete, slightly decurved; scales rather small, feebly 

 striate, 12 to 15 in advance of dorsal, 12 to 14 between dorsal and 

 adipose, 8 longitudinal rows between lateral line and anterior dorsal 

 rays; dorsal fin inserted about midway between tip of snout and base of 

 caudal ; adipose fin only a little more than half as far from base of upper 

 caudal ray as base of last dorsal ray; caudal fin forked, the lower lobe 

 the larger; anal fin rather long, its origin slightly behind base of last 

 dorsal ray, a little nearer origin of pectorals than base of caudal; ventral 

 fins reaching to or slightly past vent, inserted a little nearer tip of snout 

 than base of last anal ray; pectoral fins reaching nearly or quite to base 

 of ventrals, inserted a little nearer base of ventrals than tip of snout. 



Color silvery; the back dark green; sides with a plumbeous band, 

 which becomes almost black posteriorly, especially in the males. An 

 elongate caudal spot present, somewhat extended on base of caudal 

 rays. Breeding males with small bluish tubercles on head and margin 

 of scales. An obscure humeral spot present. Fins in breeding males 

 with barbs, making them rough to the touch. 



Of this species the present collection contains 38 specimens, ranging 

 in length from 60 to 95 mm. All were taken a Uttle above tide water in 



