162 Reviews — Ansted's Geography and Geology of Leicester. 



identification of a species, as has been asserted; lie admits that 

 there is a very great difi'erence in its shape amongst genera, but in 

 closely allied species it is so similar as to be almost identical, and 

 not to be depended upon. In his opinion, identity of outline is the 

 only certain character ; in by far the largest number of fossil otolites 

 the convex under surface is more or less bouldered, and consequently 

 the shape of the groove altered, so that, were this essential for iden- 

 tification, but few species could be recognised. The concavity of 

 the upper surface being better preserved, the task is rendered com- 

 paratively easy, and but little skill is necessary in dividing them into 

 species. The author remarks that in all fishes differing from one 

 another to that degree as to entitle them to rank as distinct species, 

 he has found the otolites in each case to be distinct and well marked. 

 This, he adds, is perhaps more than can be said of either teeth or 

 scales, and it is a generalization of the highest interest in connexion 

 with palasontological researches, as otolites are often met with in 

 Tertiary deposits, when no other vestige of the fish to which they 

 belonged has been preserved. 



laiB^VIE^WS. 



I. — On the Physical Gteogkaphy and Geology of the County 

 OF Leicester. By D. T. Ansted, M.A., F.E.S., &c. (Nichols 

 and Sons). 



THOUGH a large part of the county of Leicester presents nothing 

 very striking either in its geology or physical features, the 

 north-western portion offers a fine field to all interested in geo- 

 logical studies. It is valuable as showing within a very small area a 

 remarkable variety of rocks, while both in the pure and the applied 

 branches of the science, there are some knotty problems yet unsolved. 

 The district has naturally had a fair amount of attention already 

 paid to it. In the "Annals of Philosophy " for Jan. 1824, is a paper by 

 Messrs. W. Phillips and S. L. Kent, on the mineralogy of the 

 crystalline rocks of Charnwood Forest, and the rocks of Enderby 

 and Croft are noticed by the Eev. T. Yates (vol. ii. 2nd series, 

 Trans. Geol. Soc, p. 263). In 1836, Mr. Mammatt pubKshed his 

 " Collection of Geological Facts intended to elucidate the formation 

 of the Ashby Coal-field." This, as the title points out, was intended 

 mainly as a record of observed facts ; but the clear way in which 

 these are stated, and the few generahzations attempted to be drawn 

 from them, shew the author to have been no common man, and, con- 

 sidering the state of the science at the time of publication, are 

 deserving of the highest praise. In 1842, Mr, Jukes published in 

 Potter's History of Charnwood Forest, an account of the geology of 

 that district and its immediate neighbourhood. This little tract has 

 always seemed to us a model of clear geological description, and is 

 unmistakeably the result ot painstaking labour in the field, and not a 

 mere compilation from books. The author of the work now before us 

 has thought fit to make some disparaging remarks on its description 



