58 



of the Comniittee of Science and Correspondence at its first meeting 

 in that montb. He then stated his conviction that it \vould be found 

 to constitute the typeof a ne\v genus, intimatelyrelated to Lagoslo- 

 mu$ and ChiuchiUn, which he proposed to designate by the name of 

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

 ratton of the ilhistrious 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 ex temai distinctions on which he then 

 rehed. That opportunity having now occurred, he proceeded on 

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

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

 family to vvhich it manifestly belongs. 



As regards the bistoiy of Lagotis, although the lašt 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 carliest known to travellers in South Ame- 

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

 He believed it to be the Viscachn of atl the writers from Pedro de 

 Cieca down\vards, (including Acosta, Garcilasso, De Laet, Nierem- 

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

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

 or Peruvian acclivities of the Andes. The f .agosiomus, on the other 

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

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

 he ciled Dobrizhoffer, Jolis, D'Azara, Proctor, Head, Miers and 

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

 scribers, frora M. De Blainville to INI. Lesson. To complete the 

 history of ChinchUln be alio gavę an account of the various notices 

 reo-arding it, \vhich bave^ppeared since September 1829, the date 

 of°bis account of it in the ' Gardens and Menagerie of the Zoolo- 

 gical Society.' • 



The follou'ing characters point out the situation occupied by the 

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

 cxist betw» en them. 



Trib. Herbivora, F. Cuv. 

 Dentes molarcs eradicati, jier t oi am vitom pulpd persistente cres- 

 ccntes. 



Fam. CHINCHILLIDiE. 



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

 binis tcrnisve tiPniaUbus inter se parallelis, snbstantid vitred om- 

 nino circutndatis, constantes : coronidibus invicem exacte oppo- 

 sHis, attritit complanatis. Americae Australis incolae, gregarii, 

 subterranei, mites. Artus postici anterioribus subduplo longi- 

 oribus. Cauda producta, ad apicem supernėąue longė setosa. 



Gen. 1. Lagotis. 

 Dentes incisores -§- aattati ; molares ^3^, singiili e lamellis tribus com. 



