1. Digestive Organs of _Pelecanus Americanus_, One-third size, 99 2. Sternum of _Pelecanus Americanus_, Rather less than half size, 102 3. Stomach and proventriculus of _Plotus Anhinga_, Full size, 159 4. Trachea and stomach of _Platalea Ajaja_, Half size, 197 5. Stomach and proventriculus of _Rhynchops nigra_, Full size, 211 6. Stomach, proventriculus, and intestine of _Sula alba_, One-third size, 239 7. Stomach and œsophagus of _Ardea virescens_, Full size, 279 8. Stomach and proventriculus of _Charadrius helveticus_, 285 9. Stomach and proventriculus of _Scolopax noveboracensis_, 289 10. Digestive organs of _Ardea minor_, 301 11. Digestive organs of _Uria Alle_, 307 12. Stomach and proventriculus of _Uria Alle_ opened, 307 13. Cloaca and cœca of _Uria Alle_, 307 14. Digestive organs of _Thalassidroma pelagica_, 314 15. Stomach, proventriculus, and duodenum of _Thalassidroma pelagica_, 314 16. Stomach and intestines of _Thalassidroma pelagica_, 314 17. Digestive organs and inferior larynx of _Anas americana_, 343 18. Digestive organs and part of trachea of _Anas strepera_, 358 19. Digestive organs of _Parus atricapillus_, 381 20. Digestive Organs of _Tanagra rubra_, 393 21. Digestive Organs of _Falco cyaneus_, Half size, 407 22. Digestive Organs of _Pyrrhula Enucleator_, Full size, 420 23. Another view of the same, 420 24. Digestive Organs of _Muscicapa verticalis_, 425 25. Digestive Organs of _Troglodytes hyemalis_, 442 26. Digestive Organs of _Loxia leucoptera_, 471 27. Digestive Organs of _Falco islandicus_, 478 28. Digestive Organs of _Falco fuscus_, 529 29. Digestive organs of _Aramus scolopaceus_, Full size, 549 30. Digestive organs of _Strix funerea_, 554 31. Cœca and cloaca of _Strix funerea_, 554 32. Aperture of ear of _Strix funerea_, 554 33. External ear of _Strix Otus_, 578 34. Cœca and cloaca of _Strix Otus_, 578 35. Digestive organs of _Emberiza americana_, 583