152 SPECIMENS OF SIRENIA. 



cluced from Sir Wm. Turner's memoir on the foetus 

 of Halicore and Manatus in Journ. Anat. and Phys., 

 xxviii., 1894. They show the changes in the form 

 of the head and face of the Dugong which take 

 place during- development, from a foetus 5^^ inches 

 long to one 5 feet 4 inches, and subsequentl}^ to 

 adult growth.] 



13. Dugong, f fetal, male, diagram of, enclosed in its membranes. 



Ch., chorion, with PL, the zonary placenta, excentric in 

 position and more in proximity to the left tuba than 

 to the corpus uteri. Al., the sac of the allantois ; 

 Al.', endochorionic layer of allantois; AL", layer of 

 allantois next the amnion represented by a dotted 

 line ; Am. is in the sac of the amnion. The f(Tetus is 

 also figured on p. 145. The gravid uterus and 

 placenta are described and figured by W. Turner, 

 in his memoir on the Placentation of the Dugong, 

 Trans. Roy. Soc. Edin., vol. xxxv., part 2, 1889. See 

 figure on page 151. 



14. Dugong, profile view of the above young male fcietus, size 



of nature, 5 A inches from the muzzle along the dorsum 

 of the head and spine to the mid-point of the tail. 

 The head, tail, penis, and pectoral limb with the 

 pentadactylous manus are shown. 



Donor — C. W. de Vis, M.A., of the Queensland 

 Museum, Brisbane. 



15. Dugong, front of the face of the same fn-tus, X 2. The 



muzzle, mouth, lips, nostrils, and eyes can be recognised. 

 See upper figure on page 153. 



16. Dugong, head of a larger f fetus, size of nature ; length 



in a straight line 4| inches, zygomatic breadth 3 

 inches, from nostril to mouth If inch. See lower 

 figure on page 153. 

 Queensland. Donor — Sir Wyville Thomson. 



17. Dugong, front view of head and pectoral region, reduced 



one-half, of the ffetus figured on p. 145. The 

 characters of the face from the nostrils to the chin, 

 with the scattered hairs, are shown, and the origin of 

 the pectoral limbs. See figure on page 154 



Donor — C. W. de Vis, M.A., Queensland. 



