ANATOMY OF THE THREE-TOED SLOTH. 177 



10. Rapp, V. — "Edentnten," 2. Aufl., Tubingen. 1852. 



11. Semon.— Arch. Natiirg. 1902, p. 289. 



12. Hunter, John. — " Essays and Observations," edited by- 



Richard Owen, London, 1861, vol. ii. pp. 176-179. 



13. Gmelin.— Arch. f. mikr. Anat. 1892, pp. 1-28, Taf. 1. 



14. Mayer, -F. J. C— Froriep's Notizen, 1842, pp. 289-290. 



15. Ballowitz, E.— Anat. Anz. Jena, 1906, pp. 321-324. 



16. Gulliver, G.— Proc. Zool. Soc. 1848, p. 37. 



EXPLANATION OP THE PLATES. 



Plate I. 



A. The anterior end of a section through the head. 1 1, lips. 



B. The roof of the mouth : c, cheeks; v, vestibule; sp, soft palate. 



C. The bonj' palate of Brady pus' tridactylus. 



D. The bouj' palate of Cholwpus. 



Plate IL 



The external (A) and internal (B) structure of the stomach. In B the ventral 

 wall has been thrown upwards and to tlie ri^ht, and the dorsal cardiac compartment 

 and pylorus separated and thrown to the left- 

 A, c and B, i.i.i. : paunch. 

 A, D and B.f?, c, d,2 -. cardiac stomach. 

 A, EH and B 3 : pj'lorus. 

 Description of other letters in text. 



Plate III. 



The interior of the dorsal compartment of the cardiac stomach (A), dorsal part of 

 pylorus (B), and ventral part of pylorus (C). 



A a : rod running through the I'uminating gutter to the pylorus, h, rod 



commu'jicating with the paunch (f ). d, pleated mucosa. 

 B a : epithelial ridges bounding glandular areas (h). c, ruminating gutter. 



d, hard pleated mucosa continued from the cardiac stomach. 

 C a : pyloric sphincter with beginning of duodenum (&). c, cardiac stomach. 



Plate IV. 



A : The interior of the intestinal tract, a and B, pieces of the small intestines. 



c and D : the lower end of the ileum, colon, and rectum. 

 B : Section Lhrough the septum between cardiac stomach and paunch. 

 (." : Section of the liver. 



Proc. ZooL. Soc— 1921, No. XII. 12 



