278 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. X. 



the seventh ray of the caudal; dorsal fin with convex margin, inserted 

 posteriorly, its origin a little nearer the base of caudal than posterior 

 margin of opercle; adipose fin about midway between base of last ray 

 of dorsal and base of upper ray of caudal; caudal fin forked, the lower 

 lobe the longer, the lower fulcra free, forming a short flat spur at margin 

 of the enlarged scale of each side; anal fin rather long, its origin in ad- 

 vance of dorsal, midway between anterior margin of eye and base of 

 caudal, or somewhat nearer the latter; ventral fins reaching to or past 

 origin of anal; pectoral fins long, inserted notably nearer tip of snout 

 than original of anal. 



Color pale green above, with a dark vertebral band; sides silvery. 

 A faint lateral band present in young, scarcely visible in adult; an in- 

 distinct shoulder spot present. Fins reddish yellow; a black spot or 

 bar at base of caudal, extended to tips of outer rays of both caudal lobes. 



Numerous specimens of this species, ranging in length from 30 to 60 

 mm., were preserved. It is abundant in all streams visited on both 

 slopes of Panama, except in the Rio Chame where it is replaced by the 

 closely related species, G. intermedius. 



Habitat: Both slopes of Panama. 



28. Gephyrocharax intermedius sp. nov. 



Type No. 8945, F. M. ,N. H.; length 58 mm.; Rio Chame, 

 Panama. 



Head 4 to 4.5; depth 3.1 to 3.55; D. 9 or 10; A. 26 to 31; scales 39 to 



43- 



Body elongate, rather strongly compressed; dorsal profile anteriorly 

 straight or slightly concave; ventral outline strongly convex; abdomen 

 round in advance of ventrals, keeled from ventrals to vent; head com- 

 pressed; snout blunt, 3.7 to 5 in head; eye 2.6 to 3.4; interorbital 2.5 to 3; 

 mouth small, strongly oblique; the lower jaw a little in advance of the 

 upper; maxillary reaching slightly past anterior margin of eye; second 

 suborbital broad, with its lower posterior angle rather sharp, often 

 forming almost a right angle; teeth as in preceding species; lateral line 

 complete, curved downward anteriorly; scales striate, 1 8 to 20 in median 

 series in advance of dorsal; 5 or 6 complete rows between lateral line 

 and base of dorsal; the rows below lateral line abruptly bent downward 

 and backward toward the base of anal, 5 scales in vertical series between 

 lateral line and base of anterior rays of anal; the last scale on lower lobe 

 of caudal much enlarged in males, with a hollow space or pocket under- 

 neath, its upper edge attached to the seventh ray of caudal; dorsal fin 

 inserted posteriorly, its origin somewhat nearer base of caudal than 

 margin of opercle; adipose fin about midway between base of last ray 



