Dec. 28, 1916. Fishes of Panama — Meek and Hildebrand. 249 



7. Genus Chaetostomus Tschudi. 



ChcBtostomus Tschudi, Fauna Peruana, Pise, XV, 1840, 489 (type 



Chdztostomus loborhynchus Tschudi). 



Body elongate, anteriorly depressed, wider than deep, ventral surface 

 flat; head low, broad; snout obtuse, with a naked margin and without 

 spines or tentacles; plates on head rather smooth, without ridges or 

 carinations; back and sides covered with spinulate but not carinate 

 scutes; lower surface of head and abdomen naked; mandibular ramus 

 nearly equal to interorbital width. Adipose fin present. This genus is 

 represented by a single species in Panama. 



7. Chsetostomus fischeri Steindachner. 



ChcBiostomus fischeri Steindachner, Denkschr. K. Ak. Wiss. Wien, 

 XLI, 1879, 162, PI. IV (Rio Mamoni, near Chepo); Jordan & 

 Evermann, Bull. U. S. Nat. Mus., XLVII, 1896, 16; Regan, 

 Trans. Zool. Soc. London, XVII, Pt. Ill, 1904, 248. 

 Head 3 to 3.25; depth 5.15 to 6; D. I, 8; A. I, 5; lateral scutes 24 or 25. 

 Body anteriorly depressed; caudal peduncle posteriorly compressed; 

 dorsal profile convex; ventral surface straight and flat; head low and 

 wide, its upper surface spintdate, but without ridges or carinations; 

 snout obtuse, its margin without granules, spines or tentacles, 1.5 to 

 1.65 in head; eye 6.7 to 9.3; interorbital 2.95 to 3.6; mouth wholly 

 inferior, broad; the lips expanded, papilose, forming a sucking disc, 

 the lower lip with small lobes along its posterior margin and a small 

 barbel on its lateral margin near angle of mouth; teeth situated on the 

 ramii of the jaws, small, numerous, slender, bifid and curved inward 

 near the tips, the ramus of lower jaw i to 1.3 in interorbital; interopercle 

 with I or 2 short spines; back and sides completely covered with spinu- 

 late but not carinate scutes, 6 scutes between dorsal and adipose, 10 or 

 1 1 from anal to base of caudal; lower surface of head and abdomen com- 

 pletely naked; dorsal fin inserted a little in advance of base of ventrals, 

 somewhat nearer tip of snout than adipose fin, its base equal to distance 

 from the base of its last ray to tip of adipose, its spine 1.15 to 1.45 in 

 head; adipose fin well developed, inserted slightly nearer base of upper 

 ray of caudal than base of last ray of dorsal; caudal fin emarginate, the 

 lower rays the longest; anal fin small, its origin a little behind last ray 

 of dorsal; ventral fins reaching past origin of anal; pectoral fin large, 

 reaching beyond middle of ventrals; the spines of all the fins with 

 spinules. 



Color uniform black above; abdomen white. Tips of dorsal and 

 caudal reddish in life. 



