Dec. 28, 1916. Fishes of Panama — Meek and Hildebrand. 253 



and the female, which we designate as the type, was taken in the Rio 

 Calobre, tributary of the Rio Bayano. 



Differing from A. chagresi principally in the higher fins. The male 

 specimen has but 6 rays in the dorsal, but this may be due to an injury, 

 as the fin apparently was mutilated sometime during the fish's career. 



9. Genus Lasiancistrus Regan. 



Lasiancistrus Regan, Proc. Zool. Soc. London, XVII, Pt. Ill, 1904, 224 



& 237 (type ChcBtostomus heter acanthus Gunther). 



Body broad anteriorly; caudal peduncle posteriorly compressed; 

 head without prominent ridges, the plates not carinate; scutes on back 

 and sides spinulate but not carinate; lower svuface of head and abdomen 

 naked; margin of snout with granules and bristles; premaxillaries 

 quite as long as the dentaries; mandibular ramus notably shorter than 

 interorbital width; preopercle more or less freely movable, armed with 

 rather strong spines, the apex of each spine bent outward and forward; 

 D. I, 7; adipose fin well developed. 



10. Lasiancistrus planiceps (Meek & Hildebrand). 



Ancistrus planiceps Meek & Hildebrand, Field Mus. Nat. Hist. Pub., 



Zool. Ser., X, 1913, 79 (Rio Tuyra, Boca de Cupe, Panama). 



Head 2.6 to 2.9; depth 5.3 to 6.9; D. I, 7; A. I, 5; lateral scutes 24 or 



25- 



Body broad, low, depressed anteriorly; caudal peduncle posteriorly 

 compressed; dorsal profile nearly straight from eyes to dorsal; ventral 

 surface anteriorly broad and flat; head low and very wide; snout moder- 

 ately acute, its margin with granules and bristles, 1.6 to 1.85 in head; 

 eye 7 to 10; interorbital 2.25 to 2.45; mouth of moderate width, the 

 lips expanded, forming a sucking disc; the margin of lower lip nearly 

 smooth, with a very small barbel, shorter than eye, on its lateral margin 

 behind angle of mouth; teeth small, bifid and curved inward near the 

 tips; premaxillaries a little longer than the dentaries; the mandibular 

 ramus 3 to 4 in interorbital width; interopercle with about 20 spines 

 which vary greatly in length among individuals; sculpture of head 

 without carinations and without ridges, except for a broad, low ridge 

 on median line of snout; scutes on back and sides spinulate, the first 

 median scute behind occipital anteriorly convex, broadest at median 

 line of back; 7 scutes between dorsal and adipose, 11 or 12 between anal 

 and base of dorsal ; lower surface of head and abdomen completely naked; 

 dorsal fin high, the posterior rays when deflexed failing to reach adipose 

 by I or 2 rows of scutes, its spine longer than snout and eye, 1.3 to 1.5 



