24 



THE GEOLOGIST. 



is squeezed into nothing in one part, thickened out to thrice its 

 original diameter in another. The mass has changed its dimensions ; 

 and a limestone band could not have done this without a rearrange- 



Fig. 4. 



ment of its particles. This is, in part, what Mr. Latouche means. 

 However, we must combine the two ideas : original deposit, as bands 

 of limestone, of which we have abundant instances — the whole moun- 

 tain-limestone to wit — with that of a very frequent, nay, I am inclined 

 to believe, all but universal — alteration, and segregation afterwards. 

 In this way we may account for nearly all the vagaries of limestone — 

 and they are neither few nor small. The arrangement of the shale 

 itself in layers parallel to these concretions, nodules, and irregular 

 layers, is yet more difficult of explanation, Yet it is certain. It is 

 foliation on a small scale. Are the rocks never at rest ? 



J. W. Salter. 



ON THE GEOLOGICAL EVIDENCES OE HORSES IN 

 THE NEW WORLD. 



By Charles Carter Blake, Esq., 



Lecturer on Zoology at the London Lnsiitution. 



Before attempting to deduce any general conclusions respecting 

 the geological evidences of the genus Eqaiis in the New World, it 

 is necessary to have clear ideas respecting the geographical distribu- 

 tion of its members. In the first place, therefore, 1 give a sketch 

 of the classification and range of the existing species.* 



* Much information may be derived from the works of Owen, Gervais, Gar.. Gray, 

 Hamilton Smith, Crawfurd, Darwin, Leidy, Lubbock, Tictet, Bronu, Falconer, Sclatcr, 

 Bartlett, Nott, Gliddon, Blyth, Laird, Sykes, Youatt, Schreber, Wagner., and others, and 

 at the end of this series I shall give a list of the authors to which I have referred. 



In the geographical distribution of animals into provinces, 1 follow the philosophical 

 arrangement proposed by Dr. P. L. Sclater, who has applied the classification to orni- 

 thological arrangement with so much success. 



