176 dr. c. f. sonntag on the 



The Sacral and Caudal Vertebra. 

 Owen mentions in his ' Comparative Anatomy of the Verte- 

 brata,' that there are six sacral and eleven caudal vertebrae. In 

 both my specimens there are seven sacral and nine caudal 

 vertebras, but there is a greater degree of fusion, and less 

 distinctness, between the sacral centra in the female pelvis. 

 Flower gives the number of caudal vertebra? as 6-10. 



The Blood. 



Gulliver (16) has pointed out that the red blood corpuscles are 

 very large, and gives their measurement as 1. '2778th inch in 

 diameter in a young B. didactylus. He also states that the 

 Elephant is the only mammal with larger corpuscles. 



Summary. 

 The new facts recorded in this communication are : — 



a. The full description of the mouth and tongue. 



b. The comparison between the palates of Bradypus and 

 Cholcepus. 



c. The external relations of the compartments of the stomach, 

 and the distribution of lymphatic glands in the stomach-wall. 



d. Details of the internal structure of the stomach, and a 

 complete account of the interior of the caeca! appendage. 



e. The unusual and reptilian-like situation of the pancreas, 

 which results in complications in the peritoneum. The latter is 

 fully described for the first time in Bradypus tridaclylus. 



f. The vessels arising from the aortic arch are different to 

 previous accounts. 



g. The ligamentum arteriosum of Bradypus is described for 

 the first time. 



h. The duct papillae in the duodenum are different from the 

 form which has already been described. 



i. The comparison between the male and female pelves. 



Bibliography. 



1. Burne, R. H.— Proc. Zool. Soc. 1901, pp. 118-120. 



2. Carus. — " Erlauterungstafeln.'"' Viertes Heft, p. 19. T. viii. 



3. Cuvier. — " Legons d'anatomie comparee," Paris 1805, v. 3, 



p. 388. 



4. Francaviglia, M. — Boll. Soc. Roman, per gli studi zool., 1894. 



5. Klaatsch, H.— Morphol. Jahrb. 1892, pp. 385-450 & 609- 



716. 



6. Klinckowstrom, A. — Zool. Jahrb. Jena, 1895, p. 481. 



7. Meckel. — Syst. der verg. Anatomie, Halle 1829, v. 4, 



pp. 605-617. 



8. Mitchell, P. Chalmers. — Trans. Zool. Soc. 1905, p. 437. 



9. Pilliet. — C. R. Soc. Biol. Paris, (9), v. 3, p. 315; Journ. de 



l'Anat. et de la Phys., vol. xxii. pp. 402-423. 



