402 Mr. G. R. Waterhouse on the Classification of Mammalia. 



materials at my disposal for forming a just conclusion on this 

 point are most inadequate. 



But are we in a condition to take for basis of a classification 

 of the Mammalia, the structure of the brain ? — I think not : 

 though in the case of the Marsupialia it has afforded characters 

 serving to separate that from other sections, and to indicate its 

 proper position in the system, I am not prepared to follow those 

 naturalists who would, in our present state of information, take 

 this organ as one of primary importance in the distribution of 

 the orders of the Placental series of Mammals. I cannot adopt 

 the two great sections of this series as apparently indicated by 

 the smooth and anteriorly contracted cerebrum on the one hand, 

 and the convoluted cerebrum with its rounded anterior portion 

 on the other. Were I to do so, I should find it necessary to 

 remove some of the Lemurs from their group in the highest 

 order of the first section, and to place them in the second section. 



As regards the Cetaceans, although the condition of the senses 

 may be taken into account in considering the brain with a view 

 to forming an estimation of their intelligence, so highly an or- 

 ganized brain as is possessed by that group, it appears to me, 

 forbids its being placed at the end of the class, as has been done. 

 The stomach is very complicated, being divided into four or more 

 compartments. The dentition is very abnormal ; the teeth how- 

 ever will, I strongly suspect, bear a closer comparison in their 

 structure with the simple teeth, sometimes observed in the first 

 great carnivorous section (as in some of the Seals) than with the 

 simple teeth of the Edentata. On the whole, the Cetacea are 

 perhaps most conveniently located between the great carnivorous 

 and the herbivorous sections ; and as in the table, they may be 

 connected with the Pachydermata through the Lamantin, &c., 

 and with the Carnivora through the Seals. As regards the latter, 

 the relationship of the Cetacea to the Seals, this is certainly 

 somewhat remote, for the multilobulate kidneys, formed in both 

 groups, as well as those characters which are simply adaptive for 

 their aquatic habits, I cannot but regard as of little value as 

 indicative of affinity. 



The Manatus, Dugong and Rytina have by Cuvier been 

 associated with the true Whales. From this view De Blainville, 

 Prof. Owen*, and some other zoologists and anatomists have 

 dissented. De Blainville places the animals in question with the 

 Pachydermata, and Prof. Owen strongly inclines to the same 

 opinion : " We have seen (observes Prof. Owen) that the whole 

 of the internal structure in the herbivorous Cetacea (Dugong, 



* See this author's account of the anatomy of the Dugong in the Pro- 

 ceedings of the Zoological Society for March 1838 ; and Ann. Nat. Hist, 

 vol. ii. p. 300. 



