_White-bellied Tyrant_, i. 121. ---- _Woodpecker_, ii. 23. _White-breasted Humming-bird_, ii. 7. _White-browed Tyrant_, i. 121. _White-capped Tanager_, i. 38. _White-crested Tyrant_, i. 145. _White-eyebrowed Scytalopus_, i. 205. _White-faced Ibis_, ii. 109. ---- _Tree-Duck_, ii. 128. _White-headed Guan_, ii. 146. ---- _Tyrant_, i. 122. _White-necked Tapacola_, i. 207. _White-rumped Swallow_, i. 30. _White-sided Humming-bird_, ii. 1. _White-tailed Buzzard_, ii. 61. ---- _Kite_, ii. 71. ---- _Tyrant_, i. 112. _White-throated Cachalote_, i. 197. ---- _Humming-bird_, ii. 7. ---- _Spine-tail_, i. 179. ---- _Wood-hewer_, i. 200. _White-winged Bécard_, i. 162. ---- _Cinclodes_, i. 173. ---- _Lake-Duck_, ii. 138. _White's Ground-Finch_, i. 64. ---- _Spine-tail_, i. 181. ---- _Warbling Finch_, i. 50. _Widow Tyrant_, i. 118. _Wigeon, Chiloe_, ii. 135. _Wilson's Phalarope_, ii. 180, 181. _Wing-banded Tyrant_, i. 155. _Winter Plover_, ii. 171, 172. _Wood-bird, Brown-headed_, i. 23. _Wood-hewer, Bridge's_, i. 199. ----, _Chestnut_, i. 201. ----, _Flat-billed_, i. 199. ----, _Narrow-billed_, i. 201. ----, _Robin-like_, i. 198. ----, _Wedge-billed_, i. 199. ----, _White-throated_, i. 200. _Wood-Ibis_, ii. 108. _Woodpecker, Allied_, ii. 20. ----, _Boie's_, ii. 17. ----, _Cactus_, ii. 19. ----, _Gold-backed_, ii. 21. ----, _Pampas_, ii. 24. ----, _Red-crested_, ii. 21. ----, _Red-faced_, ii. 18. ----, _Red-fronted_, ii. 20. ----, _Schulz's_, ii. 18. ----, _Tucuman_, ii. 21. ----, _Varied_, ii. 19. ----, _White-bellied_, ii. 23. _Wood-singer, Brown-capped_, i. 21. ----, _Golden-crowned_, i. 21. ----, _Pitiayumi_, i. 20. ----, _Veiled_, i. 20. _Wren, Black-headed Reed-_, i. 13. ----, _Brown House-_, i. 13. ----, _Eared_, i. 15. ----, _Platan Marsh-_, i. 15. _Wren-like Spine-tail_, i. 188. Xanthornus pyrrhopterus, i. 107. Xanthosomus flavus, i. 98. ---- ruficapillus, i. 99. Xiphocolaptes albicollis, i. 200. ---- major, i. 201. Xolmis variegata, i. 116. _Yabirú_, ii. 106. _Yacú caraguata_, ii. 147. _Yacúhú, El_, ii. 146. _Yellow Cardinal_, i. 55. ---- _House-Sparrow_, i. 66. ---- _Seed-Finch_, i. 69. _Yellow-bellied Tyrant_, i. 137. _Yellow-billed Coot_, ii. 158. ---- _Cuckoo_, ii. 37. ---- _Saltator_, i. 42. ---- _Teal_, ii. 131. ---- _Tit-Tyrant_, i. 142. _Yellow-breasted Marsh-bird_, i. 102. _Yellow-browed Tyrant_, i. 125. _Yellow-headed Marsh-bird_, i. 98. _Yellow-marked Spine-tail_, i. 185. _Yellow-shouldered Marsh-bird_, i. 97. ---- _Song-Sparrow_, i. 60. _Yellow-striped Tanager_, i. 41. _Yellowshank, Greater_, ii. 106. ----, _Lesser_, ii. 187. _Yetapa Tyrant_, i. 124. _Ynambū azulado_, ii. 207. ---- _tatāupā_, ii. 208. _Ypecaha Rail_, ii. 150. _Zancudo_, ii. 179.