* ANIMALS. 5ia 



sloped someuliiit in the manticr of a rabbit; the teeth also are 

 formed like those of the rat kind, there being two cutting teeth 

 in each jaw ; it has a very long tail, tufted at the end ; the head, 

 the back, and sides, are covered with long asli-coioured soft 



" Such is the Iiistory of our knowledge of tliis interesting animal until 

 the arrival of a living- specimen which was brought to England by the late 

 expedition to the north-west coast of America, under tlie command of Cap. 

 tain Beechey, and liy him presented to the Zoological Society. An entire 

 skin, rendered particularly valuable iu consequence of its having the skull 

 preserved in it, was at the same time brought liome by iMr CoUie, the sur- 

 geon of Captain Beechey's vessel, and deposited in the collection of the 

 British Museum. We have thus fortunately placed within our reach the 

 means of correcting many of the errors into Avhich former \\riters have fall- 

 en with regard to it, and of giving a more complete de^criptiou of it than 

 has yet been laid before the workL 



" To begin with its generic characters. The slightest inspection of its 

 teeth was sufficient to prove that it could no longer be iissociated with the 

 groups in which it had been previously placed ; and a closer examination 

 served only to confirm the idea that it was equ;illy distinct in character from 

 every other known genus of Rodentia, In proof of the former part of this 

 assertion we borrow from the Zoological Journal Mr Yarrell's description 

 of these organs, taken from the specimen before.meutione<l, with one indis. 

 pensable alteration, of which that gentleman has himself since seen the ne. 

 cessity. He there describes the teeth as consisting of two incisors in each 

 jaw, and of four molars on either side; the three anterior of the upper jaw 

 formed of two parallel bony portions with three alternating lines of enamel, 

 and the fourth having an additional portion of bone and enamel, but smaller 

 than the two principal oues. The direction of the parallel lamins of these 

 teeth is not at right angles with the line of the maxillary bone, but inclining 

 obliquely from without backwards ; and the molars of the lower jaw are 

 placed still more obliquely than those of the upper. 



" But the examination on v\hich this statement was founded was made 

 iind r circumstances of great disadvantage, inasmuch as it is almost impos- 

 sible to obtain a distinct view of the teeth of any animal while the skull re- 

 mains within the skin, from which it was of ccuirse not allowable in the 

 present instance to remove it. The necessity for the alteration to wliich 

 we have before alluded has been rendered obvious only since the sldn was 

 transferred to the British Museum, by the extraction from the lower jaw 

 of the two anterior molars of the right side, which are now shown each to 

 possess a smaller third lamina of bone, with its corresponding enamel, placed 

 in front of, and not projecting so far externally as, the two remaining por- 

 tions of the tooth. This third Inmina is separated from that next to it by a 

 deep grove on the inner side, but on the outer there is no indication of such 

 a division; the inner surface of each of these teeth consequently ofters two 

 such grooves, wltile the outer presents no more than one. 



" In the observations appended to his account of the teeth Mr Varrell ap. 

 pears to consider the chinchilla :is nearly allied to Mr Brookes's new genua 

 I.agostomus, of which a figure arid der,cription are contained in the last pub-. 

 lished part -the tiist of the sixteenth volume) of the Liunean TrausactiouB ; 



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