_Azara's Sand-Plover_, ii. 173. ---- _Tanager_, i. 40. ---- _Trogon_, ii. 29. _Azure Jay_, i. 110. _Bahama Duck_, ii. 135. ---- _Pintail_, ii. 135. _Bailarin_, ii. 71. _Baird's Sandpiper_, ii. 184, 185. _Banduria_, ii. 112. _Bank Parrot_, ii. 41. ---- _Swallow_, i. 33. _Barn-Owl, Common_, ii. 48. _Barred Upland Goose_, ii. 123. Bartramia longicauda, ii. 189. _Bartram's Sandpiper_, ii. 189. Basileuterus auricapillus, i. 21. ---- vermivorus, i. 21. _Batitú_, ii. 189. _Bay-winged Cow-bird_, i. 95. _Bécard, White-winged_, i. 162. Bernicla antarctica, ii. 123. ---- dispar, ii. 123. ---- magellanica, ii. 123. ---- melanoptera, ii. 122. ---- poliocephala, ii. 124. _Bienteveo Tyrant_, i. 147. _Bittern, Marbled Tiger-_, ii. 104. _Black Ani_, ii. 31. ---- _Duck_, ii. 137. ---- _Rail_, ii. 149. ---- _Vulture_, ii. 89. _Black-and-chestnut Warbling Finch_, i. 49. _Black-and-yellow Thickbill_, i. 43. _Black-and-yellow-crested Tyrant_, i. 157. _Black-billed Cuckoo_, ii. 38. _Blackbird, Argentine_, i. 4. _Black-crowned Tyrant_, i. 115. _Black-faced Ibis_, ii. 110. _Black-headed Duck_, ii. 130. ---- _Finch_, i. 45. ---- _Reed-Wren_, i. 13. ---- _Siskin_, i. 64. ---- _Thrush_, i. 4. ---- _Tyrant_, i. 157. _Black-necked Tanager_, i. 37. _Black-tailed Skimmer_, ii. 193. _Black-winged Dove_, ii. 142. _Blackish Finch_, i. 54. ---- _Tyrant_, i. 141. _Blue Heron_, ii. 99. ---- ----, _Little_, ii. 101. ---- _Tanager_, i. 39. _Blue-and-yellow Tanager_, i. 39. _Blue-billed Tyrant_, i. 127. _Blue-fronted Amazon_, ii. 47. _Blue-winged Teal_, ii. 130. _Boat-tail, Chopi_, i. 108. _Boie's Woodpecker_, ii. 17. Bolborhynchus aymara, ii. 46. ---- monachus, ii. 43. Bolborhynchus rubrirostris, ii. 46. _Bonaparte's Sandpiper_, ii. 185. _Boyero_, i. 101, 116. _Brazilian Cormorant_, ii. 91. ---- _Lochmias_, i. 174. ---- _Stilt_, ii. 179. ---- _Teal_, ii. 133. _Bridges's Wood-hewer_, i. 199. _Bright-cheeked Grebe_, ii. 204. _Broad-billed Tyrant_, i. 136. _Brown Buzzard_, ii. 63. ---- _Cinclodes_, i. 172. ---- _Cuckoo_, ii. 35. ---- _Gallito_, i. 207. ---- _House-Wren_, i. 13. ---- _Martin_, i. 35. ---- _Pintail_, ii. 134. ---- _Tinamou_, ii. 207. _Brown-capped Wood-singer_, i. 21. _Brown-crested Spine-tail_, i. 177. _Brown-fronted Spine-tail_, i. 178. _Brown-headed Wood-bird_, i. 23. _Brush-loving Fly-snapper_, i. 12. Buarremon citrinellus, i. 41. ---- (Atlapetes) citrinellus, ii. 223. Bubo crassirostris, ii. 50. ---- magellanicus, ii. 50, 51. ---- virginianus, ii. 50. Bucco chacuru, ii. 30. ---- maculatus, ii. 30. ---- striatipectus, ii. 30. _Buff-breasted Sandpiper_, ii. 190. _Burmeister's Cariama_, ii. 162. ---- _Humming-bird_, ii. 2. _Burrito_, ii. 150. _Burrowing Owl_, ii. 52.