nae a eS 
Dec, 28, 1916. FisHEs or PANAMA— MEEK AND HILDEBRAND, 263 
Body depressed; anterior profile straight or gently convex; head 
without ridges; snout not produced, broadly obtuse, its margin granu- 
lar, with short bristles on sides in male, its length 1.7 to 1.8 in head; eye 
without orbital notch, 6.5 to 8.7; interorbital 3.1 to 3.6; lips reverted, 
papillose; maxillary barbel shorter than eye; predorsal plates 3, without 
carinations; lateral keels anteriorly obscure or wanting, coalesced on 
t5th or 16th scute; 17 or 18 scutes from anal to base of caudal; 5 to 8 
rows of small plates on belly between lateral series; dorsal fin anteriorly 
not greatly elevated, not much longer than head, its origin over base of 
ventrals; caudal fin forked, the outer ray of both lobes produced, the 
upper one bearing a filament; anal fin anteriorly moderately elevated, 
the spine somewhat shorter than head; ventral fins reaching to or a 
little past origin of anal; pectoral fins reaching a little beyond base of 
ventrals, 1.05 to 1.23 in head. 
Color dark grayish brown, with obscure darker blotches above; 
pale below. Fins usually with indistinct dark markings. 
This species is represented by many specimens, ranging from 40 to 
250 mm. in length. This fish was found only in the Rio Bayano and 
Rio Tuyra basins. It is rare in the former but abundant in the latter. 
This species is rather closely related to O. tamane Regan, from which 
it differs in having from 5 to 8 longitudinal rows of plates on belly 
between the lateral series, instead of only 3. The snout in the present 
species is more obtuse and the fins are lower. 
Family III. Callichthyidz. 
Sides with 2 series of lateral scutes; mouth terminal, lower lip not 
reverted; air bladder vestigiary, one on each side of the coalesced verte- 
bre and entirely surrounded by a bony capsule, the cavity communicat- 
ing with the exterior by means of a long narrow slit in the temporal 
plate. Caudal vertebre normal, the neural and hemal spines spine- 
like, separated from each other. 
13. Genus Hoplosternum Gill. 
Hoplosternum Gill, Ann. Lyc. Nat. Hist. N. Y., VI, 1858, 395 (type 
Callichthys levigatus Valenciennes=Callichthys littoralis Hancock). 
Body with 2 lateral series of scutes, overlapping along median line, 
forming a depression; gill-membranes confluent with the skin of the 
isthmus; two pairs of nuchal plates between humeral and coracoid 
process; coracoids exposed; 2 pairs of maxillary barbels; no mandibular 
