DEC. 28, 1916. FISHES OF PANAMA MEEK AND HILDEBRAND. 251 



8. Ancistrus chagresi Eigenmann & Eigenmann. 



Ancistrus cirrhosus (non Cuvier & Valenciennes) Kner & Steindachner, 



Abhandl. K. Beyer. Ak. Wiss. Munchen, X, 1864, 61 (Rio Chagres). 

 Ch&tostomus cirrhosus Gunther, Trans. Zool. Soc. London, 1866, 478 



(Rio Chagres). 

 Ancistrus chagresi Eigenmann & Eigenmann, Proc. Cal. Ac. Sci., 2nd Ser., 



II, 1889, 47 (Rio Chagres), and Occ. Pap. Cal. Ac. Sci., I, 1890, 



446. 

 Xenocara chagresi Regan, Trans. Zool. Soc. London, XVII, Pt. 3, 1904, 



256 (Rio Chagres). 



Head 2.55 to 2.9; depth 4.7 to 5.75; D. I, 7; A. I, 3 or 4; lateral scutes 

 24 to 26. 



Body anteriorly broad, depressed; caudal peduncle posteriorly com- 

 pressed; dorsal profile anteriorly gently convex; ventral surface straight 

 and flat; head broad, the interorbital width nearly equal to depth of 

 body, 2.05 to 2.3 in head; snout obtuse, the margin naked; naked portion 

 broad in the males and narrow in females, in the former with well 

 developed tentacles on the margin and a V-shaped patch above near tip 

 of snout; tentacles varying much in number and length among indi- 

 viduals; females with only a few short tentacles along or a little below 

 the margin of snout; length of snout 1.6 to 1.75 in head; eye 7 to u; 

 mouth rather wide; the lips expanded, with straight margin; barbel on 

 lateral margin of lower lip minute; the premaxillaries quite as long as the 

 dentaries; mandibular ramus 2.45 to 3.2 in interorbital width; teeth 

 slender, bifid, curved inward near the tips; interopercle with from 9 to 

 15 spines of various lengths, which also vary much among individuals, 

 longer in the male than in the female; sculpture of head without ridges 

 or carinations; scutes on back and sides not carinate, but with strong 

 serrations on their margins; occipital bordered by 3 scutes; the second 

 median scute without a distinct median suture; 6 or 7 scutes between 

 dorsal and adipose, n or 12 from anal to base of caudal; lower surface 

 of head and abdomen naked; dorsal fin moderately elevated, the poste- 

 rior rays when deflexed failing to reach adipose by at least one row of 

 scutes, the spine 1.2 to 1.5 in head; base of dorsal scarcely equal to 

 distance from base of last ray to tip of the spine of the adipose; adipose 

 fin well developed; caudal fin with a straight oblique or slightly concave 

 margin, the lower rays the longest; anal fin small, its origin at vertical 

 from base of last ray of dorsal; ventral fins reaching past origin of anal; 

 pectoral fins reaching past base of ventrals, but failing to reach the 

 middle of these fins, the spine notably shorter than head. 



Color uniform dark above or occasionally with small greenish spots 

 on head and predorsal region; abdomen usually with pale green spots 



