Reviews — The Palceontographical Society. 565 



upper schists, the white marble shows thin streaks of talcose, 

 lustrous mica, and the same is the case in the veined and breccia 

 varieties. The violet-veined marble called paona%zi owes its delicate 

 violet tint to streaks of minute oligist and pyrite crystals. The breccia 

 of the metalliferous Stazzema division also exhibits mineral and 

 micaceous streaks, while the bright-red, wavy marks are due to 

 infiltrations of iron. 



Statuary marble, graduating from grezzoni below to ordinary white 

 and bianco chiaro above, occurs in inconsiderable depth more or less in 

 all the principal Carrara quarries from Piastra to Ravaccione, Canal 

 Grande, Fantiscritti, Fontana, Colonnata, and Gioja, while the most 

 abundant and celebrated, because purest and most durable statuario 

 occurs in the Polvaccio, Crestola, and Betogli quarries of the Carrara, 

 and in the Altissimo and Falcovaja quarries of the Seravezza divisions. 



The most striking and conclusive phenomenon in relation to the 

 statuary marble is that, apart from the lower zones of the marble 

 beds, it occurs also in the very heart of ordinary white marble. This 

 is conspicuously the case in the Polvaccio quarry already mentioned, 

 where the finest statuario forms the nucleus of the saccharoidal mass, 

 and gradually passes into ordinary white marble, the latter being 

 here, as the equivalent of madrimacchie, marked by a zone of dusty 

 dark streaks, and hence termed macchiato. The intimate association 

 of statuary and ordinary marble is thus conclusively demonstrated. 



There is throughout the marble beds in their different varieties 

 and gradations no faulting, nor any evidence of crushing, which, if it 

 existed, would of course render the marble industrially worthless. 

 So far from the marble beds being in any way associated or con- 

 temporaneous with the older schists, they form one and all an 

 integral part of the Triassie series which, from the principal grezzoni 

 zone to the upper schists, in stages of metamorphism varying according 

 to the effect of pressure and high temperature upon the original rock 

 material, constitute the lower Mesozoic formation of the Apuan Alps. 1 



REVIEWS. 



I. — The Pliocene Mollusca of Great Britain, being Supple- 

 mentary to S. V. Wood's Monograph of the Crag Mollusca. 

 By F. W. Harmer, F.G.S. Palasontographical Society's Mono- 

 graph, 4to, 1914, pp. 201-302, pis. xv-xxxii. 

 IN the year 1847 the Palseontographical Society issued its first 

 annual volume, consisting only of Part I of the Crag Mollusca, 



1 The evidence adduced in this paper is wholly adverse to the view recently 

 expressed by Professor Bonney in this Magazine (July, 1915, p. 294) that the 

 schists and marbles of Carrara are most probably of Archaean age. 



An additional feature of interest in the Apuan Alps is the evidence of former 

 glaciation. Stoppani, as early as 1872, was the first to point out a detritus 

 cone of striated material at the lower end of the Ami Valley (E. Inst. Lomb. 

 Sci. Nat., vol. v, p. 733 ; also Atti Soc. It. Sci. Nat., Aprile, 1875). Similar 

 deposits occur at high levels in the Carrara valleys and on the slopes of 

 Pisanino, Sumbra, and Corchia ; and Zaccagna met with conspicuous roches 

 moutonnies on a calcareous schist ledge in the Granolazzo (Upper Serchio) 

 Valley, about 50 metres in length. A more detailed notice of these glacial 

 phenomena would exceed the scope and limit of the present paper. 



