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



Oxyloricaria panamensis Regan, Trans. Zool. Soc. London, XVII, Pt. 



Ill, 1904, 301 (Rio Magdalena; Panama). 

 Oxyloricaria frenata Regan, Trans. Zool. Soc. London, XVII, Pt. Ill, 



1904, 302, PI. XVIII, fig. 2 (N. W. Ecuador). 

 Oxyloricaria dariensis Meek & Hildebrand, Field Mus. Nat. Hist. Pub., 



Zool. Ser., X, 1913, 81 (Rio Tuyra and Rio Bayano basins, Panama). 



Head 4.06 to 5.3; depth 8.5 to 13; D. I, 7; A. I, 5; lateral scutes 33 



to 35. 



Body long, slender, depressed throughout; head without ridges; 

 snout produced, pointed, its margin granular or with short bristles 

 at sides in male, its upper profile concave, 1.57 to 1.7 in head; eye 7.5 

 to 9.5s; interorbital 3.1 to 4.2; lips reverted, papillose; maxillary barbel 

 shorter than eye; predorsal plates 3, without carinations; lateral keels 

 anteriorly obscure, coming close together in young and uniting in the 

 adult on the 17th to the 20th scute; 19 or 20 scutes from anal to base of 

 caudal; dorsal fin anteriorly much elevated, notably longer than head, 

 its origin over base of ventrals; caudal fin forked, both lobes produced, 

 the outer ray bearing a filament; anal fin high, the undivided ray or 

 spine longer than head; ventral fins reaching opposite or past base of 

 anal; pectoral fins reaching opposite lower third or lower half of ventrals, 

 the spine usually equal to length of head. 



Color plain olive above; pale below. Anterior rays of dorsal black, 

 the black sometimes more or less broken up into spots; caudal fin with 

 a dark longitudinal bar on each lobe; other fins all with more or less 

 dusky on interradial membranes. 



Of this species we have 86 specimens, ranging in length from 50 to 

 260 mm. One small specimen is from the Rio Calobre, tributary of the 

 Rio Bayano and all the others are from the Rio Tuyra Basin, where it 

 is quite common. 



A study of specimens from Colombia and Ecuador along with our 

 specimens shows that there are quite a number of synonyms under this 

 species. The fact that the lateral keels in the young are not completely 

 united while in the adult they are, in part at least accounts for the 

 numerous names that have been proposed. 



Habitat: Pacific slope of Panama, both slopes of Colombia, south to 

 Ecuador. 



18. Oxyloricaria citurensis Meek & Hildebrand. 



Oxyloricaria citurensis Meek & Hildebrand, Field Mus. Nat. Hist. 



Pub., Zool. Ser., X, 1913, 82 (Rio Cupe, Cituro, Panama). 



Head 4.55 to 5.1; depth 8.5 to 10; D. I, 7; A. 6; lateral scutes 

 300131. 



