Cope.] ■ ^64 [Aug. 19 



the presence of the lateral line, and in having two series of premaxillary 

 teeth instead of one, of which the external is simple and not tricuspid. 

 There are also two series of teeth on the dentaries of Piabucina. The 

 suborbital bones of this genus are large. 



Character specijicus. I'orm medium, head elongate, broad and flat above, 

 interorbital width 2.5 times in length. Diameter of orbit nearly three 

 times in length of head, equal to length of muzzle. Length of head one- 

 third of total without caudal fin. Greatest depth one-fourth of same. 

 Scales large, 1. series 6 at ventrals ; transverse (above 1. line) 16. Radii, 

 D. 12 ; A. 11 ; V. 9 ; caudal deeply forked. 



Color light olive ; top of head and muzzle, ventral, anal, and dorsal fins 

 blackish. Caudal fin red, dusky medially. 



There are three longitudinal ridges on the cranium above, of which 

 the median is very weak. Total length M.068 ; length to opercular 

 margin, .0175 M.; to basis of ventral, .0285 M.; to basis of anal, .042 M.; 

 to bases of caudal, .052 M. From Pebas, Equador ; Hauxwell's collection. 



Aphyocharax FiLiGEKtJS. Cope sp. nov. 



Head small, the length contained five times in total, without caudal fin ; 

 height 4.25 times in the same. Eye three times in length of head, a little 

 exceeding muzzle. Dorsal fin originating half way between lines of 

 origin of ventrals and anal. Anal long, the anterior rays much prolonged, 

 filiform, extending backwards to the last fifth of the length of the base. 

 Dorsal elevated ; Eadii, D. 10 ; A. 28- L.l. scales 38 ; tubes on a few of 

 the anterior only ; 1. tr. 13. Premaxillary teeth seven on each side, max- 

 illaries numerous, occupying most of the margin of the bone. Color olive 

 above, yellowish below, lower lobe of caudal blackish. Length OM. .06. 



This, the second species of this genus just described by Gtinther (Proc. 

 Zool. Loc. London, 1868, 245), differs from the type species, A. pusillus, 

 in the longer anal fin (there are only 18 rays in the latter), with much 

 prolonged anterior radii, the shorter head, the more numerous maxillary 

 teeth, &c. 



From Pebas, Eastern Ecuador, Hauxwell's Collection. Dedicated to 

 the discoverer, a successful naturalist and explorer. 



RoEBOiDES BicoBNis. Cope sp. nov. 



Radii D 11, A 51 ; scales 1. tr. 18 — 16 ; the back is gibbous ; the outline 

 of the front plane ; the muzzle slightly descending, and 

 overhanging the mandible ; depth one-third of length, 

 without caudal fin; length of head 3.5 times in -same; 

 eye large, 3.5 times in head ; inter-orbital region narrower, 

 convex ; two horn-like teeth projecting forwards ; two 

 small ones on each side posteriorly, directed outwards ; 

 mandible with four equal conic processes ; mandible with 

 fi)ur canines ; premaxillary teeth irregular, maxillaries 

 sparse ; pectorals and ventrals extending beyond basis 

 of anal; length 0.07 M. ; to ventrals .02 M. ; to anal .025 

 M. ; origins of dorsal and anal opposite. 



