236 Bulletin American Museum of Natural History. [Vol. XXXVI, 



(546) Merganetta colombiana Des Murs. 



Merganetta colombiana Des Mtjbs, Rev. Zool., 1845, p. 179 (Colombia). 

 Merganetta levcogenys Scl. & Salv., P. Z. S., 1879, p. 543 (Frontino). 



Found by us only in the Central Andes where it is not uncommon on 

 the rapid rivers of the Subtropical Zone. Our four specimens are males, one 

 being adult, the others immature with the underparts white, unmarked ex- 

 cept for the bars on the sides and flanks. The male, taken in the Rio Toche, 

 October 23, had the testes much enlarged, and is just completing a molt in 

 which the tail was renewed, indicating the near approach of the nesting 

 season. 



Two of the immature birds, taken at Salento, Sept. 25, are acquiring 

 new wing-quills but the rectrices are very worn and the shafts of the six 

 central feathers are projected 30-34 mm. beyond the vanes of the feather 

 proper. The basal half of this projection is devoid of barbs, while the api- 

 cal half is finely set with barbs about 2 mm. in length. In the third imma- 

 ture bird, taken at El Eden, Nov. 13, the remiges are fully grown and these 

 peculiar projections are wanting on the much worn tail-feathers. Possibly 

 they represent a preceding plumage and disappear by breaking off. The 

 point at which the break is to occur is indicated by a transparent space just 

 beyond the vane of the feather. If, as seems probable, these rather stiffly 

 barbed, projecting shafts constitute the rectrices of the natal down, they 

 are doubtless of assistance to the young bird in clambering up on the water- 

 washed rocks which form its natural resting-places. 



Salento, 2; Rio Toch6, 1; El Eden, 1. 



Obder PELECANIFORMES. 

 Family PHALACROCORACIDiE. Cormorants, Shags. 



(549) Phalacrocorax vigua vigua ( Vieill.). 



Hydrocorax vigua Vieill., Nouv. Diet. d'Hist. Nat., VIII, 1817, p. 90 (Para- 

 guay). 



Carbo hrasilianust Cass., Proc. Acad. N. S. Phila., 1860, p. 197 (R. Truando). 

 Phalacrocorax vigua Allen, Bull. A. M. N. H., XIII, 1900, p. 124 (Bonda). 

 Carho vigua Hellm., P. Z. S., 1911, p. 1209 (Noanamd). 



