348 Reviews and Notices of Booh 



Introductory Text- Book of Geology. By David Page, 

 F.G.S., Edinburgh and London. 1854. w. C, 12mo. 



We heartily congratulate Mr Page on the production of a Geo- 

 logical Text-Book, which is at once clear and succinct, and in 

 many respects well adapted to the beginner. In his preface he 

 states, that " the utmost care has been taken to present a simple 

 but accurate view of his subject;" and while we consider that 

 this statement is justified in the main by the mode in which he 

 has fulfilled his task, he has fallen into a few inaccuracies w T hich 

 we think it necessary to point out. 



His arrangement of the " Silurian system" (p. 58) is perfectly 

 correct, and he has placed the " Tilestones" at the top of the 

 Ludlow series of rocks, for he is well aware that the " Tilestones" 

 contain fossils eminently Silurian. Orthoceras bullatum, Rhyn- 

 conella nucula, Chonetes lata, Lingula cornea, &c, &c. At the base 

 of the " Tilestones" we find the " bone bed" of the Upper Ludlow 

 rock; and there, with the remains of Silurian shells and crustaceans, 

 for the first time in the geologic scale and the history of the 

 planet, we meet with the fragments of fish. These fish are peculiar 

 to the Silurian system, and the same ichthyolites have been found 

 by Prof. Phillips in strata of the Upper Ludlow shales consider- 

 ably lower than the " bone bed." " Each stratum," says Sir 

 R. Murchison, speaking of the lowest member of the Old Bed 

 Sandstone and the fish beds of the Upper Ludlow, " is a fact con- 

 firmatory of the view of Agassiz, that those animals are very exact 

 indicators of rocks." 



Those who were present in the Geological Section at the British 

 Association at Liverpool (September 1854), when Mr Page, with 

 Sir R. Murchison's Siluria in his hand, was called to order by Sir 

 Charles Lyell upon this very point, can hardly suppose that it was 

 through ignorance our author penned the following passage in his 

 recapitulation of the Old Bed Sandstone : — " Characterized on its 

 lower margin by strata containing the remains of fishes, and in 

 this respect separated from the Silurian, which is devoid of such 

 fossils, and defined, on its upper margin, by the rarity of that 

 vegetation which enters so profusely into the composition of the 

 carboniferous rocks, there can, in general, be no difficulty in 

 determining the limits of the old red formation." 



At page 63 he also "remarks that remains of fishes'' must be 

 " regarded as marking the dawn of the Old lied Sandstone epoch, 

 rather than as belonging to the close of the Silurian ;" and to 

 which we reply that were mammalia found associated with the 

 fossils of the Upper Chalk, he might argue, with equal truth, that 

 the upper cretaceous deposit appertained to the epoch of the 

 Eocene tertiaries ! This is not all : a similar mis-statement is ap- 



