.M A .VI iM A LI A HOD E N T I A . .' V. ) 



wanting also iii j\[//o.cttn Dri/a*. According to the dentition, it belongs to 

 Ilie division Glis, but tlie frontal bone is as iu M. Nltela, and the lower jaw 

 is perforated posteriorly, which is not the case iu Glis, I have counted in 

 all 51 vertebra; viz. 13 dorsal, 6 lumbar, 3 sacral, aud 25 caudal. 



Of Gfapluuriis ccqwiisix, a more accurate description than that previously 

 given has appeared in A. Smith's 'Illustrations of the Zool. of S. Africa,' 

 (xvii, pi. 39.) 



CHINCHILLINA. P. Gcrvais has prepared the article Chinchilla for the 

 ' Diet. Univ. d'Hist. Nat.' (iii, p. 584), but he is nevertheless not all aware 

 that, since 1835, two species have been distinguished by Wiegmann. 



PSAMMORYCTINA s. ORYCTERiNA. Burmeister would re- 

 move Psammoryctes from this group, and refer it, on the 

 contrary, to the Cunicularia (Wurfmaiisen), (1. c.) 



He thinks that the short tail, and the posterior molars becoming smaller, 

 correspond to the type of the Bristle-Rats (Schrotmause). When I esta- 

 blished tliis family I had not myself inspected any specimen of Psammoryctes, 

 and was obliged to rely upon the accounts of others. Having, however, 

 obtained a specimen of it with, the cranium taken out, I see clearly that 

 Psammoryctes can in no way be regarded as the type of the Bristle-Rats, 

 but that it is a transition form leading immediately from the latter to 

 Geofhyelnts. "With this, the form of the cranium and of the incisors most 

 nearly agrees ; the contracted orbital opening also of the Cunicularia 

 begins to enlarge in some degree in Georhychus, and in this way leads to 

 /'w/,///M</v/,'/r.v, in which it is still wider, and on this account corresponds 

 with that of the Bristle-Rats (Schrotmause). Taking into consideration 

 these highly important circumstances, I am induced, from its approachment 

 to Georhychus, from the shortness of the ears and tail, and, as it appears to 

 me, from the stronger development of the anterior in comparison with 1 In- 

 posterior extremities, to place the genus Psammoryctes, as now defined by 

 me, next to the Cunicularia (Wurfmause.) With the separation, however, 

 of this genus from the Bristle-Rats (Schrotmause), the name of the family 

 must be changed, on which account I now propose, instead of PSAMHOIIYC- 

 TINA, that of ORYCTEKINA. 



An accurate description, accompanied with beautiful 

 figures of two new Brazilian Bristle-Rats (Schrotmause), 

 Nelomys pictus and Echinomys inermis, has been given by 

 Pictet, in the Mem. de la Soc. de Physique et d'Hist. 

 Nat. de Geneve, x, Ire partie, 1843. Both species agree 



