184 FISHES OF WESTERN SOUTH AMERICA 
Hypostomus Lacépeéde, 1803, Hist. Nat. Poiss., V, 144, guacari = plecostomus; 
Cuvier and Valenciennes, 1840, Hist. Nat. Poiss., XV, 489, plecostomus; 
Jordan, Evermann, and Clark, 1928 (1930), Rept. U.S. Comm. Fish., Part II, 130. 
Type: Hypostomus guacart Lacépede = Loricaria plecostomus Linnaeus 
Throughout the Atlantic drainage to the foothills of the Andes of Peru, 
Magdalena basin, Guayaquil 
Snout granular; no spines or bristles about the head; adipose fin present; sides 
and back completely enclosed within plates; first scute of lateral series posterior to 
clavicle and temporal plate, separating the second entirely from the temporal; snout 
with granular plates to the margin; venter naked or with small granular scales. 
165. HyposToMUS EMARGINATUS Cuvier and Valenciennes 
Hypostomus emarginatus Cuvier and Valenciennes, 1840, Hist. Nat. Poiss., XV, 500, Brazil; 
Kner, 1854, Denksch. KIX. Akad. Wiss. Wien, VII, 260. 
Plecostomus emarginatus Giimther, 1864, Cat. Fish. Brit. Mus., V, 233; 
Steindachner, 1882, Denksch. IKIx. Akad. Wiss. Wien, XLIII, 112; 
Eigenmann and Eigenmann, 1888, Proc. Cal. Acad. Sci., (2), I, 167; 
Eigenmann and Eigenmann, 1890, Occ. Papers Cal. Acad. Sci., I, 400; 
Regan, 1904, Trans. Zool. Soc. London, XVII, 210; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 406; 
Fowler, 1939 (1940), Proc. Acad. Nat. Sci. Phila., XCI, 233, Contamana. 
Plecostomus scopularius Cope, 1871, Proc. Acad. Nat. Sci. Phila., 55 and 286, pl. xvi, figs. 1 and 2, 
Ambyiacu R. 
Plecostomus biseriatus Cope, 1871, Proc. Acad. Nat. Sci. Phila., 285, Ambyiacu. 
Plecostomus virescens Cope, 1874, Proe. Acad. Nat. Sci. Phila., XXVI, 187, Nauta; 
Cope, 1878, Proc. Amer. Phil. Soc., XVII, 681, Peruvian Amazon; 
EFigenmann and EHigenmann, 1890, Occ. Papers Cal. Acad. Sci., I, 408. 
Amazons, Para to Peruvian Andes, Guianas, R. Magdalena 
15360, 3, 170-245 mm., Iquitos, Amazon, Allen, September, 1920. 
15362, 1, 159 mm., Gosulimacocha, Rio Morona, Allen, October, 1920. 
15363, 5, 23-242 mm., Rio Morona, Allen, October, 1920. 
15364, many, largest 231 mm., Yurimaguas, Rio Paranapura, Allen, November, 1920. 
15365, 3, 122-193 mm., Contamana, Rio Ucayali, Allen, August, 1920. 
15361 and 15366, many, 25-310 mm., Yurimaguas, Allen, November, 1920. 
166. Hyposromus pLEcostoMuUs (Linnaeus) 
Acipenser plecostomus Linnaeus, 1758, Syst. Nat., ed. x, 238. 
Loricaria plecostomus Linnaeus, 1766, Syst. Nat., ed xii, 508, America. 
Hypostomus plecostomus Cuvier and Valenciennes, 1840, Hist. Nat. Poiss., XV, 489, Guiana; 
Kner, 1854, Denksch. KK. Akad. Wiss. Wien, VII, 263. 
Plecostomus plecostomus Eigenmann and Eigenmann, 1888, Proc. Cal. Acad. Sci., (2), I, 168, 169, 
Brazil; 
Eigenmann and Eigenmann, 1890, Occ. Papers Cal. Acad. Sci., I, 406; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, IIT, 403; 
Pearson, 1937a, Proc. Cal. Acad. Sci., (4), X XIII, 96, Pusoc, upper Maranon. 
Plecostomus bicirrhosus Gronow, 1754, Cat. Fish., 158; 
Giinther, 1864, Cat. Fish. Brit. Mus., V, 231, Guianas, Para; 
Steindachner, 1881, Denksch. Kx. Akad. Wiss. Wien, XLIII, 109; 
Boulenger, 1887, Proce. Zool. Soc. London, 277. 
