308 VIEW OF THE FAUNA OF BRAZIL 



nary quality. In several caverns I have found remains of a 

 fossil species, which approaches it very nearly, but at the 

 same time exhibits some specific distinctions, and moreover, 

 rather exceeds it in size. Another species [Ech. elegans, mihi) 

 is of the size of our large house-rat (Mus decumafms), to 

 which it bears a perfect external resemblance, and is furnished 

 with a very long, bare tail. It is armed with spines, and 

 displays a purity of colour that makes it a very pretty little 

 animal. I have discovered the fossil remains of a species, 

 which, judging by the fragments I possess, agrees well enough 

 with this. A third species {Ech. sulcidens) I am only ac- 

 quainted with from the abundant remains it has left upon the 

 surface of the soil in the caves, where they form no inconsi- 

 derable portion of the vast heaps of bones I have described 

 in my preceding communication. I have also found traces 

 of a species belonging to the fossil period, which seems to 

 agree very closely with this recent animal ; but I have again 

 to lament that the fragments I as yet possess, are not suffi- 

 cient to enable me to pronounce decidedly on its identity. 



A fourth species {Ech. laticeps, mihi) is rare, and I have 

 not met with any trace of a corresponding species among 

 the fossil bones of these caverns. 



Equally peculiar to South America as the preceding genus, 

 to which it also bears a near affinity, is the genus SynethereSy 

 of which there are only two known species, Syn. prehensilis, 

 L., and Syn. insidiosa, Licht. ;' the last of the size of a rab- 

 bit, the former twice as large. The antediluvian world also 

 possessed this animal form, but, with the character peculiar 

 to that ancient fauna, of a gigantic size ; for the fragments 

 that I have, betoken a creature very little inferior in bulk to 

 the wild hog. The fossil species, moreover, presents a nearer 

 resemblance to the smaller existing species {Syn. insidiosa) 

 than to the larger {Syn. prehensilis), so that it would be classed 

 by those zoologists who make a generic division between 

 these two species, under the genus Sphiggurus. 



Each of the remaining genera of this family, viz. Sciurus, 

 Zepus, Anoema, Dasyprocta, Coelogenys, and Hydrochoerus, 

 contains at present but a single species. 



Of the first genus I have hitherto found no trace whatever 



' I cannot agree with the views of some of our modern zoologists who 

 make a generic distinction between these two species {Synetheres and 

 Sphiggurus, F. Cuv.), inasmuch as they sufficiently agree in their habits, 

 external appearance, and even in their internal structure, especially in their 

 dental system. The principal difference lies in the great development of 

 the nasal and frontal bones, which the former possesses, in common with 

 the Hystrices of the old world, but which is not seen in the latter. 



