Pterylography of the Hoatzin. 371 



3. Gadow, H. Bronu^s Klassen und Ordnungeu des Tliier- 

 reichs. Vogel. Anatomischer Theil, pp. 550, 569 

 (1891). 



4. . Ibid. SystematischerTheil, pp. 175-178 (1893). 



5. Garrod, a. H. Notes ou points in the Anatomy of the 



Hoatzin {Opisthocomus cristatus). P. Z. S. 1879, 

 p. 109. 



6. Grant, W. R. Ogilvie. Catalogue of the Birds in the 

 British Museum, vol. xxii. p. 523 (1893). 



7. Newton, A. Dictionary of Birds, p. 421 (1893). 



8. NiTzscH, C. L. Pterylography. Ray Society. P. 108, 

 pi. vi. figs. 12, 13 (1866). (Translated from the 

 German.) 



9. Perrin, J. B. On the Myology of Opisthocomus cris' 

 tatus. Trans. Zool. Soc. vol. ix. p. 353, pis. Ixiii.-lxvi. 

 (1875). 



10. Pettigrew, J. B. Animal Locomotion, pp. 129, 130 



(1883). 



11. Pycraft, W. P. HheY^mg oiArchceopteryx. 'Natural 



Science,' vol. iv. pp. 355, 358, 359 (1894). 



12. QuELCH, J. J. On the Habits of the Hoatziu, Opistho- 

 comus cristatus. Ibis, 1890, p. 327. 



13. Sharpe, R. B. Classification of Birds, p. 70 (1891). 



14. Young, C. G. On the Habits and Anatomy of Opis- 

 thocomus cristatus, Illig. Notes Leyden Mus. x. p. 169, 

 pi. 8 (1888). 



EXPLANATION OF THE PLATES. 



(All the figures are original.) 



Plate IX. 



Fig. 1. — Dorsal aspect of aa adult Opisthocomus, showing the arrange- 

 ment of the pterylae. The shaded parts represent the apteria. The 

 relative sizes of the feathers are indicated by large and small dots, 



Apt.a.sup. Apterium alse superius. 

 Apt.cap. „ capitis. 



Apt.t.lat. „ trunci laterals. 



Apt.sp. „ epinale. 



2 D 2 



