u 



ME. W. P. PYCRAFT ON THE 



14. Hodgson, B. II. — Journ. Asiat. Soc. Bengal, vol. vi. (1837) p. 362. 



15. Howes, G. B. — "On some Abnormalities of the Frog's Vertebral Column," Anat. Anzeig., Jahrg. 



1886. 



16. Howes, G. B. — "Notes on Variations and Development of the Vertebrse and Limb Skeleton of the 



Amphibia," P. Z. S., 1893. 



17. LvDEKKER, R. — Cat. Foss. Birds Brit. Mus., 1891. 



18. Milne-Edwards, A. — Recherches pour servir a I'Histoire des Oiseaux Fossiles de la France, vol. i. 



(1867-68). 



19. Milne-Edwards, A. — "Observations sur les Affinites zoologiques du Genus Photodilus," Nouv. 



Arch. Mus., 2' ser. t. i. (1878). 

 20 Newton, A. — Dictionary of Birds. 1896. 



21. Parkek, G. H. — "Variation in the Vertebral Columns of Necturus," Anatom, Auzeig., Bd. xi. 



(1896). 



22. Peck. — "Variation of Spinal Nerves in Caudal Region of Pigeon," Journ. Morphol., vol. iii. (1893). 



23. Uidewood, W. G. — ^"On the Development of the Vertebral Column in Pijya and Xenopus,'" Anatom. 



Auzeig., Bd. xiii. (1897). 



24. Sharpe, R. B. — A Review of Recent Attempts to Classify Birds. 1891. 



25. Sharpe, R. B. — Cat. Striges Brit. Mus., vol. i. (1875). 



26. Sharpe, R. B.— Hand-list of Birds, vol. i. (1899). 



EXPLANATION OF PLATES 1 and 2. 



Explanation of letters. 



