346 FISHES OF WESTERN SOUTH AMERICA 
471. RivuLus pERUANUS Regan 
Aplocheilus peruanus Regan, 1903, Ann. Mag. Nat. Hist., (7), XII, 626; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 454. 
Rivulus peruanus Regan, 1912, Ann. Mag. Nat. Hist., (8), X, 496; 
Eigenmann, 1922, Mem. Carnegie Mus., IX, 183. 
Perim, Peru, elevation 800 m. 
Simons collection taken near Huaraz, but I find no information as to the exact 
location of Perim, or whether it is on the Atlantic or Pacific slope; two specimens, 
types, 55 mm. long. 
472. RivuLUS UROPHTHALMUsS Giinther 
Plate XXII, figs. 1 and 2 
Rivulus urophthalmus Giinther, 1866, Cat. Fish. Brit. Mus., VI, 327; 
Regan, 1912, Ann. Mag. Nat. Hist., (8), X, 498; 
Henn, 1916, Ann. Carnegie Mus., X, 110; 
Myers, 1927, Ann. Mag. Nat. Hist., (9), XIX, 126. 
Rivulus brasiliensis FKigenmann (in part), 1910, Rept. Princeton Univ. Exped. Patagonia, III, 
454. 
Amazons and Guianas 
16185, 1, female, 47 mm., brook, Iquitos, Allen, September, 1920. 
16186, 1, male, 49 mm., Yurimaguas, Allen, November, 1920. 
473. RivuLus MIcRopus (Steindachner) 
Fundulus micropus Steindachner, 1863, Sitzb. KI<. Akad. Wiss. Wien, XLVIII, 184; 
Cope, 1878, Proc. Amer. Phil. Soc., XVII, 695. 
Rivulus micropus Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 454; 
Regan, 1912, Ann. Mag. Nat. Hist., (8), X, 500; 
Myers, 1927, Ann. Mag. Nat. Hist., (9), XIX, 125. 
Trinidad, Venezuela, Rios Negro and Peruvian Amazon 
Subfamily: ORESTIATINAE 
Orestiasini, Orestiasiformes Bleeker, 1860, Ichth. Arch. Ind., II, 43; 483. 
Orestiinae Regan, 1911, Ann. Mag. Nat. Hist., (8), VII, 325; 
Orestiatinae Myers, 1931, Stanford Univ. Publ. Biol. Sci., VI, iii, 12. 
Genus 195: ORESTIAS Cuvier and Valenciennes 
Orestias Cuvier and Valenciennes, 1846, Hist. Nat. Poiss., XVIII, 221; 
Garman, 1895, Mem. Mus. Comp. Zool., XIX, 147; 
Pellegrin, 1904, Bull. Soc. Zool. France, X XIX, 92; 
Pellegrin, 1906, Poiss. Lacs Hauts Plat. Amé4r. Sud, 126. 
Type: Orestias cuviert Valenciennes 
Lake Chinchaycocha southward, Titicaca basin 
“Basisphenoid and opisthotic bones absent; post-temporal not forked, its 
upper limb joined to epiotic; parasphenoid without lateral process to alisphenoid; 
