Zoological Society. 149 



skeleton of an animal recently living in the Menagerie, and exhibited 

 in illustration of a paper "On the Family of Chinchillidce, and on a 

 New Genus referrible to it," the commencement of which he read. 

 The animal in question was purchased, in June 1832, from a dealer, 

 who was completely ignorant of the locality from which it was ori- 

 ginally obtained; and was brought by Mr. Bennett under the notice 

 of the Committee of Science and Correspondence at its first meeting 

 in that month. He then stated his conviction that it would be found 

 to constitute the type of a new genus, intimately related to Lagosto- 

 mus and Chinchilla, which he proposed to designate by the name of 

 Lagotis, adding the specific denomination of Cuvieri, in commemo- 

 ration of the illustrious naturalist, whose irreparable loss the world 

 of science was just then called upon to deplore. He deferred, how- 

 ever, the completion of his account of the animal, until he should 

 be enabled, at its death, to add the dentary and other internal cha- 

 racters, to the more obvious external distinctions on which he then 

 relied. That opportunity having now occurred, he proceeded on 

 the present occasion to redeem his pledge, and also to take a ge- 

 neral view of the history, zoological characters and anatomy of the 

 family to which it manifestly belongs. 



As regards the history of Lagotis, although the last of the three 

 animals constituting the family to come under the cognizance of 

 zoological science, Mr. Bennett stated that he had little doubt 

 that it was in fact the earliest known to travellers in South Ame- 

 rica, which he had no hesitation in assigning as its native country. 

 He believed it to be the Viscacha of all the writers from Pedro de 

 Ciega downwards, (including Acosta, Garcilasso, De Laet, Nierem- 

 berg, Feuillee, Ulloa, Vidaure, Molina, Schmidtmeyer and Steven- 

 son,) who have mentioned that animal as an inhabitant of the Western 

 or Peruvian acclivities of the Andes. TheLagosto?nus, on the other 

 hand, is clearly the Viscacha described by so many travellers as co- 

 lonizing the vast plains eastward of that great chain. Among these 

 he cited DobrizhotTer, Jolis, D'Azara, Proctor, Head, Miers and 

 Haigh. For its zoological history he referred to its various de- 

 scribers, from M. De Blainville to M. Lesson. To complete the 

 history of Chinchilla he also gave an account of the various notices 

 regarding it, which have appeared since September 1829, the date 

 of his account of it in the 'Gardens and Menagerie of the Zoolo- 

 gical Society.' 



The following characters point out the situation occupied by the 

 three animals in the Order Rodentia, and the generic differences that 

 exist between them. 



Trib. Herbivora, F. Cuv. 

 Denies molares eradicati, per totam vitam pulpd per&istente cres- 

 centes. 



Fam. CHINCHILLIDiE. 



Dentes incisores superiores simplices ; molares *^J, e lamellis osseis 

 binis ternisve taenialibus inter se parallelis, substantia" vitred om~ 

 nino circumdatis, constantes: coronidibus invicem exacte oppo- 



