786 PATAGONIAN EXPEDITIONS: ZOOLOGY. 



Description. — Adult male, P. U. O. C. 7927, May 20, 1898, Arroyo 

 Eke, Patagonia, A. E. Colburn (type of A. poliosoma Scott). Total 

 length, 9.30 inches; wing, 5.30; culmen, 1.15; tail, 4; tarsus, 1.30. 

 Above brownish drab ("hair brown" of Ridgway), buffy white supercili- 

 aries, ear coverts and sides of the face streaked with the same ; wings 

 dark brown edged with dull white ; middle tail feathers dark brown be- 

 coming white at tip, outer web of others white, dusky at base of inner 

 ones, and inner web white for about the terminal third ; under parts 

 more ochraceous than the upper side ; throat dull white streaked with 

 blackish ; under tail coverts white, crissum and flanks tinged with tawny ; 

 bill and feet black. 



Geographical Range. — Patagonia (Chubut valley, Port Desire, Santa 

 Cruz, etc.), 50 to 38° S. latitude. Only the single specimen above de- 

 scribed was obtained by the Expedition. 



Mr. Peters found it sparingly at Huanuluan and El Escorial. 



Genus MYIOTHERETES Reichenbach. 



Type. 



Myiotheretes Reichenb. Av. Syst. Nat. t. Ixvi. (1850) . M. ritfiventris. 

 Geographical Range. — Western South America from Colombia south- 

 ward to Peru ; eastern South America from Uruguay southward to ex- 

 treme southern Patagonia (Palli Aike ; Rio Chico de Gallegos). 



Myiotheretes rufiventris (Vieillot). 



Tyrannus rufiventris V\€\\\o\., Encyc. Meth. p. 856 (1823), based on the 



"Pepoaza vientre roxizo" of Azara (Montevideo). 

 Pepoaza variegata d'Orbigny, Voy. Amer. Merid. p. 349, pi. 39, fig. 2 



(1835-1844) (Patagonia). 

 Description. — Adult female, P. U. O. C. 7577, near Rio Coy, Patago- 

 nia, September 30, 1896. Total length, 8.70 inches; wing, 5.90; culmen, 

 .72; tail, 3.56; tarsus, 1.45. Above gray strongly washed with olive, 

 feathers of the crown with obscure blackish shaft streaks ; primaries black, 

 the inner ones black on the outer web and tawny on the inner, becoming 

 whitish toward the tip ; secondaries light chestnut, broadly white toward 

 the tip, tertials blackish with white borders, coverts gray with white bor- 

 ders ; tail black with narrow white tip and outer web of outer pair nar- 

 rowly bordered with white ; throat and breast ashy gray, passing into 



