THE PLAOKNTATION OF PERAMELES. 439 



16. Owen, R. — 'On the Anatomy of Vertebrates,' vol. iii, 1868. 



17. Stikling, E. C. — "On some Points in the Anatomy of the Female 



Organs of Generation of the Kangaroo, especially in Relation to the 

 Acts of Impregnation and Parturition," ' Proc. Zool. Soc.,* London, 

 1889. 



18. Wilson, J. T., and Hill, J. P. — " Observations upon the Development 



and Succession of the Teeth in Perameles ; together with a Contribu- 

 tion to the Discussion of the Homologies of the Teeth in Marsupial 

 Animals," ' Quart. Journ. Micr. Sci.,' vol. xxxix, 1897. 



19. Balfour, F. M.— "On the Evolution of the Placenta, and on the Possi- 



bility of employing the Characters of the Placenta in the Classification 

 of tiie Mammalia," ' Proc. Zool. Soc.,' London, 1881. 



20. HuBRECHT, A. A. W. — " Die Keimblase von Tarsius," ' Festschrift fiir 



Carl Gegenbaur,' Leipzig, 1896. 



21. Semon, R. — "Enstehung und Bedeutung der embryonalen Hiillen und 



Anhangsorgane der Wirbelthiere," ' C. R. 3'"« Congres Int. de Zoo!.,' 

 Leydeu, 1896. 



EXPLANATION OF PLATES 29—33, 



Illustrating Mr. Jas. P. Hiirs paper on "The Placentation of 



Perameles." 

 ("Contributions to the Embryology of the Marsupialia/' I.) 



All sections drawn were outlined by means of Zeiss's camera lucida. 



List of Common Reference Letters. 



all. a. Allantoic artery, all. c. Allantoic cavity, all. cap. Allantoic capil- 

 lary, fl//. c/. Allantoic canal. «//. e?^^ Allantoic entoderm, all. mes. hW&wio- 

 chorionic mesenchyme. all. v. Allantoic vein. bil. omph. Bilaminar 

 omphalopleure. c. m. Circular musculature, coe. Extra-embryonic spianch- 

 nocoele. cce. w. Inner (coelomic) wall of allantois. c/i. ed. Chorionic ecto- 

 derm, ch. ed'. Isolated chorionic ectoderm cell. c. t. Interglandular con- 

 nective tissue, ed. Ectoderm, ent. Entoderm, ex. syn. Syncytium beyond 

 allantoic placental area. gl. Uterine gland, p. hue. Polynuclear leucocytes. 

 pi. a. Allantoic placental area. pi. syn. Syncytium of allantoic placental area. 

 som. Somatic mesoderm of chorion, s. t. Sinus terminalis. 5y«. Syncytium. 

 syn. c. Capillary of syncytium, syji. I. Syncytial lobule, vase. omph. Vascular 



