1035 



TOXODON. 



TOXOTES. 



1036 



external ones very large, curved, and with their sockets extending 

 backwards in an arched direction through the intermaxillary bones to 

 the maxillary, and terminating, without diminishing in size, imme- 

 diately anterior to the grinding teeth, where the large persistent pulps 

 of these incisors were lodged. In form and relative size these teeth 

 must have resembled the dentes scalprarii of the Rodents. 



The molar teeth no less present a close approximation in their 

 form and structure to the molar teeth of the Herbivorous Rodents. 

 They are seven in number on each side of the upper jaw, and, from 

 the form of the sockets, appear to have corresponded with each other 

 in structure. 



"After summing up the different affinities, or indications of affinity, 

 which are deducible from this most curious and interesting fossil 

 mammal, we are led to the conclusion, assuming it to have had extre- 

 mities cased in hoofs, that it is referrible to the order Pachydermata ; 

 but the structure, form, and kind of teeth in the upper jaw prove 

 indisputably that the gigantic Toxodon was intimately related to the 

 Rodent order. From the characters of this order, as afforded by the 

 existing species, the Toxodon however differs in the relative position 

 of the supernumerary incisors, and in the number and direction of 

 the curvature of the molars. If moreover the lower jaw, next to be 

 described, belong, as I believe, to the Toxodon, the dental character of 

 the genus will be 



j 7 7 



"Incisores, - ; Pro Laniariis Diastema; Molares, - -. 



6 7 7 



" The Toxodon again deviates from the true Rodentia, and resembles 

 the Wombat [MAHSUPIATA] and the Pachyderms in the transverse 

 direction of the articular cavity of the lower jaw. It deviates from 

 the Rodentia, and resembles the Pachydermata in the relative position 

 of the glenoid cavities and zygomatic arches, and in many minor 

 details already alluded to. 



Skull of Toxodon Platcntii, profile. 



Top view of the Skull of Toxodon ttatouu 



gknll of Taxation Platentit, seen from behind. 



"The affinity above alluded to is too obvious to have escaped 

 popular notice, and the Capybara, from its aquatic habits, has 

 obtained the name of Water-Hog. It is highly interesting to find 

 that the contjuent to which this existing aberrant form of Rodent is 



peculiar should be found to contain the remains of an extinct genus 

 characterised by a dentition which closely resembles the Rodent type, 

 but manifesting it on a gigantic scale, and tending to complete the 

 chiin of affinities which links the Pachydermatous with the Rodent 

 and Cetaceous orders." 



Penultimate molar tooth (upper jaw) of Toxodon Plateusis. 



Incisor tooth of lower jaw of a Toxodon. 



a, grinding surface of penultimate upper molar tooth of Toxodon Platentii; 

 b, grinding surface of a corresponding molar tooth of the lower jaw. 



Fragment of anterior part of lower jaw of a Toxodon, with teeth in situ. 

 (All from Owen.) 



TOXO'STOMA. [MEHULIDJ:.] 

 TOXOTES. [ABCHJSB-FIBH.] 



