Bibliographical Notices. 411 



the movement of certain animals would sometimes present themselves 

 more favourably in one direction than in another. 

 : " Evidences of the accumulation of the osseous portions of elephants, 

 rhinoceroses, and other animals of several of the same species, the 

 remains of vyhich occur in accumulations beneath those formed at the 

 cold or ' glacial ' time, are considered to have been detected also above 

 them, together vnth the remains of some animals not previously in- 

 habiting the area of the British Islands and adjacent portions of the 

 continent of Europe. This subject offers a fertile field for the labours 

 of an observer. Though much may have been accomplished, much 

 remains to be done, and it will require his especial care to see, that 

 amid the new lakes and river-channels formed, when the ground took 

 that general configuration which we now find, a re-arrangement of 

 bones, washed out of the older deposits, containing remains of the 

 Elephas primigenius. Rhinoceros tichorhinus, and their contemporary 

 mammals, and carried into the newer lacustrine and fluviatile beds, 

 may not occasionally be such as to mingle the osseous remams of the 

 species of one time with those of another." 



Among the more interesting portions Qf the work to which we 

 would direct the attention of the student, is the section devoted to 

 the consideration of the mode of accumulation of detrital and fossiU- 

 ferous rocks, in which points of the highest geological interest are 

 fully discussed. As a general fact, we must dismiss from our minds 

 the notion, that the present distribution of dry land and water in the 

 world bears any relation to that of past time, for it is now generally 

 conceded that the earth has passed through a series of physical 

 changes, and has been successively tenanted by forms of animal and 

 vegetable life, adapted to each varying condition as it arose, — indica- 

 tions of periods of repose or of the continuance of certain given con- 

 ditions over the whole area of the globe itself. 



The difhculty, therefore, with which the geologist has to contend 

 in his investigation of the physical geography of different geological 

 times, is the obliteration of the ancient landmarks, either by denuda- 

 tion and the washing away of previous formed materials, or the sub- 

 sequent accumulation of detrital matter over the ancient surface. We 

 are glad to find the interest manifested of late in seeking out the 

 boundaries of any ancient land and the actual margins of the seas of 

 the time, which points, to some extent, have been successfully followed 

 out by the labours of the Geological Survey, for it has been ascer- 

 tained, from the researches of Prof. Ramsay, " that during the de- 

 posit of the Silurian rocks of Wales and Shropshire, there was a time 

 when the older accumulations now forming the district of the Long- 

 mynds, rose above the sea, and were bounded by beaches ; while a 

 part of the Silurian series, named the Caradoc sandstones, was being 

 deposited adjacent to them. Again, in the Malvern district. Prof. 

 J. Phillips has showu that about the same geological date a portion 

 of the syenites of the Malvern hills must have been above the sea -^ a 

 beach deposit, in which there arc angular fragments of the pre-existing 

 rocks, occurring on their western flank. In both cases organic re- 

 mains are mingled with the shore accumulations, and Prof. E. Forbes 



