. Dec. 28,1916. Fisues or PANAMA— MEEK AND HILDEBRAND. 247 
ee. Margin of snout bearing tentacles, long and numerous in the 
male, short and few in female; mandibular ramus much narrower 
than interorbital. Ancistrus, p. 250. 
dd. Margin of snout with granules and bristles; mandibular ramus 
notably shorter than interorbital. Lasiancistrus, p. 253. 
bb. Adipose and anal fins wanting; margin of snout granular, bear- 
ing short bristles; mandibular ramus nearly equal to interorbital. 
Leptoancistrus gen. nov., p. 254. 
aa. Body long and slender; caudal peduncle very long, strongly 
depressed; adipose fin wanting. 
f. Eye with a distinct orbital notch; teeth usually bifid, and in 
small or moderate numbers. Loricaria, p. 255. 
ff. Eye without an orbital notch; teeth setiform, numerous. 
Oxyloricaria, p. 261. 
6. Genus Plecostomus Gronow. 
Plecostomus Gronow, Mus. Ichth., I, 1754, 24 (sp.); Gronow, Zooph. 
Gronov., 1763, 127; Bleeker, Nederl. Tijdschr. Dierk. I, 1863, 77 
(type Plecostomus brasiliensis Bleeker=Loricaria plecostomus Lin- 
_ meeus). 
Hypostomus Lacépéde, Hist. Nat. Poiss., V, 1803, 144 (type Hypostomus 
guacari Lacépéde). 
Body elongate; back and sides completely covered with carinate 
bony scutes; first scute of lower lateral series separating the second scute 
entirely from the temporal plate; lower surface of head and abdomen 
naked or covered with small granular scales; snout granular; opercle 
with or without marginal bristles, firmly attached to the interopercle 
and not capable of independent movement; premaxillaries and dentaries 
of about equal length, each with slender bifid teeth; adipose fin present; 
caudal fin emarginate. A large genus of which but one species is repre- 
sented in the rivers of Panama. 
6. Plecostomus plecostomus (Linnzus). 
Loricaria plecostomus Linnzus, Syst. Nat., Ed. 12, I, 1766, 508 
(America). 
Hypostomus guacart Lacépéde, Hist. Nat. Poiss., V, 1803, 145 
(America). 
Loricaria flava Shaw, Gen. Zool., V, 1805, 38, Pl. ror. 
Hypostomus plecostomus Schomburgk, Fishes Brit. Guiana, I, 1841, 139 
(Rio Branco). 
Hypostomus robinit Gill, aged egy 28 apa N. Y., VI, 1858, 46 
(Trinidad). 
