a one Stila el 
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. Manchen, X, 1864, 61 (Rio Chagres). 
Chetostomus cirrhosus Ganther, Trans. Zool. Soc. London, 1866, 478 
(Rio Chagres). 
Ancistrus chagrest Eigenmann & Eigenmann, Proc. Cal. Ac. Sci., 2nd Ser., 
II, 1889, 47 (Rio Chagres), and Occ. Pap. Cal. Ac. Sci., I, 1890, 
446. 
Xenocara chagresit 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 11; 
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, 11 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 
