DEC. 28,1916. FISHES OF 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. Anctstrus, 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; Sleeker, Nederl. Tijdschr. Dierk. I, 1863, 77 

 (type Pkcostomus brasiliensis Bleeker=Lon'can'a plecostomus Lin- 

 naeus). 



Hypostomus Lac6pde, Hist. Nat. Poiss., V, 1803, 144 (type Hypostomus 

 guacari Lace"p6de). 



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 (Linnaeus). 



Loricaria plecostomus Linnaeus, Syst. Nat., Ed. 12, I, 1766, 508 



(America). 

 Hypostomus guacari Lace*pede, Hist. Nat. Poiss., V, 1803, 145 



(America). 



Loricaria flava Shaw, Gen. Zool., V, 1805, 38, PI. 101. 

 Hypostomus plecostomus Schomburgk, Fishes Brit. Guiana, I, 1841, 139 



(Rio Branco). 

 Hypostomus robinii Gill, Ann. Lye. Nat. Hist. N. Y., VI, 1858, 46 



(Trinidad). 



