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



44. Piabucina panamensis Gill. 



Piabucina panamensis Gill, Proc. Ac. Nat. Sci. Phila., 1876, 336 (Rio 

 Frijoles, Panama); Eigenmann & Eigemnann, Proc. U. S. Nat. Mus., 

 XIV, 1891, 52; Jordan & Evermann, Bull. U. S. Nat. Mus., XLVII, 

 1896, 332; Regan, Biol. Cent. Amer., Pisces, 1907, 167 (Rio Tripoli, 

 misprint for Rio Frijoles) ; Eigenmann, Repts. Princeton Univ. Exp. 

 Patagonia, III, Pt. IV, 1910, 439; Evermann & Goldsborough, 

 Proc. Biol. Soc. Wash., XXIII, 1910, 3 (Gatun, Panama Canal 

 Zone) . 



Head 3.5 to 4.2; depth 4 to 4.6; D. 8 or 9; A. 10 or 11; scales 

 28 or 30. 



Body elongate, little compressed, dorsal and ventral outlines about 

 evenly convex, the dorsal region not elevated; caudal pedtmcle com- 

 pressed, its depth 2.16 to 2.7 in head; head low, not much deeper than 

 wide at margin of preopercle; snout conical, 3.7 to 4.5 in head; eye 3.4 

 to 5.8; mouth moderate, lower jaw projecting; maxillary reaching about 

 middle of eye; teeth tricuspid, in a single series in upper jaw, 2 series in 

 lower jaw, the outer the larger and about 30 in number; gill-rakers short; 

 scales large, regularly placed, 12 in median line in advance of dorsal; 

 dorsal fin inserted about midway between margin of preopercle and tip 

 of adipose; adipose fin well developed in all specimens at hand; caudal 

 fin covered with small scales at base, its margin convex; anal fin with a 

 sheath of scales at base, its margin convex; ventral fins inserted in 

 advance of dorsal; pectoral fins a little longer than ventrals, failing to 

 reach base of ventrals by 4 or 5 rows of scales, 1.45 to 1.6 in head. 



Color brownish above, lighter below; a dark lateral band extending 

 from above posterior angle of opercle to base of caudal, situated on 

 median line of side. This band is broad at shoulder, gradually becom- 

 ing narrower along side; posteriorly it is often broken up into spots. 

 Dorsal fin with an obscure dark spot at base, fins otherwise unmarked. 

 When swimming in the water, a large golden spot appears on the back, 

 involving the base of the dorsal fin. This area becomes slightly darker 

 than remainder of back in preserved specimens. 



This species is represented in the present collection by 148 specimens, 

 ranging from 60 to 205 mm. in length. It was taken at the following 

 localities: a. On the Atlantic slope at Toro Point, Agua Clara, Rio 

 Indio on Upper Chagres, Gorgona, Empire, Culebra and Porto Bello. 

 b. Pacific slope at Corozal, Araijan, Culebra, Rio Calobre, tributary of 

 the Bayano, and Cerro Azul. 



This fish is usually found in the upper courses of streams on rocky 

 bottom where it is difficult to catch with a seine. However, it takes 

 the hook readily when baited with fresh meat. Its distribution appears 



