410 W. G. iilDEWOOD. 



14. Roth, S. — "Descripciou de los restos encontrados en la caverna de 



Ultima Esperauza," ' Revista del Museo de la Data,' ix. La Plata, 

 1899, pp. 421—453. 



15. SoRBY, H. C. — "On the Green Colour of the Hair of Sloths," ' Journ. 



Linn. Soc.,' xv, London, 1881, pp. 337 — 341. 



16. Waldeyer, W. — ' Atlas der Menscli. und Thierischen Haare,' Jahr 



1884. 



17. VVelckek, H., and Kifhn, J. — " Ueber die Entwickiuug und den Bau der 



Haut und der Haare bei Bradypus," ' Abhaudl. naturf. Gcbell. zu 

 Halle,' ix, 1864, pp. 17— 72d, two plates. 



18. Woodward, A. Smith, and Moreno, F. P. — "On a Portion of Mam- 



malian Skin, named Neomylodon Listai, from a Cavern near 

 Consuelo Cove, Patagonia," ' Proc. Zoot. Soc.,' London, 1899, pp. 

 144 — 156, three plates. 



19. Woodward, A. Smith. — "On some Remains of Grypotherium 



(Neomylodon) Listai and associated Mammals from a Cavern near 

 Consuelo Cove, Patagonia," 'Proc. Zool. Soc.,' Loudon, 1900, pp. 

 64—79, five plates. 



EXPLANATION OF PLATE 26, 



Illustrating Dr. W. G. Ridewood's paper " On the Structure 

 of the Hairs of Mylodon Listai and other South 

 American Edentata. 



al. Alga. CO. Cortex, cu. Cuticle, eco. Extra-cortex, m. Medulla. 



EiG. 1. — Bradypus tridactylus. Hair, one and a iialf times natural 

 size. 



Pig. 2. — Terminal portion of hair (a in Fig-. 1). x 100. 



Fig. 3. — Transverse section taken through the thickest part of the hair 

 (b in Fig. 1). X 100. 



Fig. 4. — Corresponding part of hair seen longitudinally ; the upper part in 

 optical section, the lower part witii the surface in focus. X 100. 



Figs. 5 and 6. — Transverse section and side view of basal part of hair 

 taken in the position indicated by c in Fig. 1. x 100. 



Fig. 7. — Portion of one of the fine hairs of the under-fur, and a transverse 

 section of the same, x 100. 



