Mr. Bennett on the ChinchilHdee. 493 



Of Lagostomus, as I liave before observed. Dr. Meyen enumerates 

 three species. The two first of these represent the animals respectively 

 figured by the late Mr. Brookes and by M. Lesson under the name of 

 Lagostomus trichodactylus, which he considers as distinct on account of 

 the differences observable between the two figures. These consist in the 

 small and curved claws of the hinder foot in the former, contrasted with the 

 large size and nearly straight direction of the same organs in the latter ; in 

 the habit; and in the shape of the tail. The misapprehension is undoubtedly 

 very excusable ; but it may serve to shew how dangerous it is to rely on 

 figures only in the discrimination of species. As regards the first pre- 

 sumed distinction, I have already observed (p. 57 of my paper) that 

 " in this particular the figures given by Mr. Brookes are defective, as 

 exhibiting the claws far smaller and more curved than is natural." A 

 reference to the descriptions of M. F. Cuvier and M. de Blainville, both 

 taken from Mr. Brookes's specimen while living, will confirm the 

 accuracy of this observation; the latter in particular {Desm. Mammal. 

 No. 508) describing the middle toe of the hinder foot as furnished with 

 a very strong claw. On the second point, the habit, it need only be 

 observed that both figures were taken from stuffed skins by artists who 

 had never seen the living animal ; and who could consequently give only 

 their own conjectural ideas of its natural appearance when in a living 

 state. On the third, it may be observed that some obscurity is to be 

 feared, M. de Blainville having described the animal while living as having 

 its tail truncate and mutilated, and Mr. Brookes's skin and skeleton 

 being both provided with perfect tails. I may add that a fine skin now 

 in the possession of the Zoological Society agrees in all essential particu- 

 lars with the animal figured by M. Lesson, and as far as my recollection 

 goes, with that which formerly formed part of Mr. Brookes's Museum. 

 The figure given by the latter should only be considered correct in so far 

 as it is borne out by the descriptions of MM. F. Cuvier and de Blainville, 

 which should be referred to in connexion with it. 



The third species of Lagostomus enumerated by Dr. Meyen is the 

 Eriomys Chinchilla of Dr. Lichtenstein, figured and described in that 



