398 Da KNOX on the Dentition of the Dugong, and on the 

 Zoological Arrangement of the Dugong. 



I 



In the inquiry, which, at the Meeting of the 21st Decem- 

 ber 1829, I had the honour to submit to the Society, the denti- 

 tion of the dugong was considered. It was shewn in that me- 

 moir, that an insuperable objection lay against the views as to the 

 succession of the tusks of the dugong, promulgated first by the dis- 

 tinguished English anatomist, Sir EVERAIID HOME, and adopted, 

 so far as I know, by most continental ones. The observations 

 which were then submitted to the Society shewed, that in two 

 adult crania of the dugong, there were two kinds of tusks, quite 

 distinct from each other in their form, and that this difference 

 seemed specific, as not being referrible to age. In considering 

 the character I speak of as specific, I do not go beyond the or- 

 dinary rule of zoological investigation ; but, whether or not this 

 determination be the correct one, I feel yet assured, that these 

 differences in the form of the tusks, in the adult crania of the du- 

 gong, do not depend on age, and this is all I contend for at pre- 

 sent. 



There is a fact to which I beg leave to call the attention of 

 the Society, before I quit this subject. The milk-tusks of the 

 dugong have never been seen by any one ; that is, I have not 

 heard of the existence of any preparation shewing the germs of 

 the milk or permanent teeth, together or in succession, and in 

 such a way as to leave no doubt on the subject. They may 

 exist, inasmuch as there is nothing in the economy of this inte- 

 resting animal forbidding such a belief ; but I repeat that they 

 never have been seen by any one ; so that it seems to me but 

 right, that, previous to all further speculations as to the natural 

 history of the animal, efforts were made to perfect, in some mea- 

 sure, its anatomy, on which alone can the zoologist found any 

 rational inquiry. 



