366 PROCEEDINGS OF THE ACADEMY OF [Juue, 



OBSERVATIONS UPON THE PLACENTA AND YOUNG OF 

 DASYPUS SEXCINCTUS. 



BY HEXRY C. CHAPMAN, M. D. 



The Edentata, so called by Cuvier on account of the teeth being 

 so imperfectly developed or absent in the representatives of the 

 order, includes a very heterogeneous assemblage of animals — ant- 

 eaters, sloths, armadillos — differing very much in their internal 

 organization, especially in the character of their placeutation. 

 Thus the placenta in the Cape ant-eater, Orijctwopiis, is deciduous 

 and, according to some authorities,^ discoidal, to others^ zonular 

 inform. In theTamandua, T. tetradactyla, it is possibly deciduous 

 and discoidal;' in the sloths, Chokcpus Hoffnianni, it is decidu- 

 ous and loboid in form;'' in the Pangolin, Manis, f non-decidu- 

 ous and diffuse;" in certain species of armadillos, e. g. Dasypus 

 novemcindus, possibly deciduous and discoidal/ 



In view of the fact that such profound differences exist in the 

 placentation of the Edentata, il is hoped that the following obser- 

 vations upon the placenta and young of the six-banded armadillo 

 born in the Philadelphia Zoological Garden and submitted to the 

 author for examination by JNIr. A. E. Brown, Secretarv of the 

 Society, will prove acceptable. It should be mentioned in this 

 connection that in the case of the placenta of Dasypus novemcinc- 

 tas as described by Milne-Edwards," four foetuses wei'e found 

 enclosed in one chorion. Such a disposition, far from being an 

 abnormal one, would seem to be that usually obtaining, at least in 

 that species of armadillo, since the same number of foetuses were 



* T. H. Huxley, Introduction to the Classification of Animals, LondoD, 

 1869, pp. 98, 104. 



'^W. Turner. Journal of Anat. and Phys., Vol. 10, 1876, p. 69o. 



^ A. Milne-Edwards, Ann. des Sciences Nat., CinquiemeS6rie,Zool., XV, 

 1672, p. 2. 



*W. Turner, Trans, Royal Society of Edinburgh, Vol. XXVII, 1876, 

 pp. 76, 78. 



^T. H. Huxley, op. cit., p. 104. 



''' Alpb. Milue-Edwards, Annalcs des Sciences Naturrllcs, Sis.ii:me Sitrie, 

 Zoologie, VIII, 1879, pp. 2, 3. 



' Oj). cit., p. 2. 



