IXX PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



are surrounded bj a husk or crust containing much mica or talc and 

 other substances, and are imbedded in the common crystalline lime- 

 stone. This husk is called " Madre-macchia ;" and the more it is 

 developed, the purer is the marble within. 



This is precisely the manner in which the pure white alabaster of 

 Florence is found in the gypsum -quarries of Castellina, as I have 

 already described it *. I have also visited the marble-quarries of 

 Carrara but never observed this peculiar structure there. No doubt 

 the marble varies much in quality in different localities and on dif- 

 ferent hills, but it always occurs in large amorphous fissured masses, 

 all trace of stratification being removed by the metamorphism it has 

 undergone. If the author has not, as I suspect, confounded the 

 structure of the alabaster with that of the statuary-marble, it will 

 be a curious coincidence to find that both occur under such similar 

 circumstances. The explanation of this structure given by the author 

 is no doubt correct, viz., that during the metamorphosis of the lime- 

 stone or gypsum, the foreign particles mixed up with it were 

 driven out by chemical action and formed the Madre-macchia ; and 

 the more this was done, the more perfect was the marble or ala- 

 baster. 



Prof. Eeuss has published in the ' Transactions of the Imperial 

 Academy of Sciences at Yienna,' a paper on a portion of the fauna 

 of the Upper Ohgocene formation of Germany, viz. the Foramini- 

 fera, Anthozoa, and Bryozoa. The author's former works on these 

 minute forms are well known ; and, after alluding to the previous 

 partial publications of other authors, he observes that, owing to the 

 large mass of materials placed in his hands by numerous palaeonto- 

 logists as the results of recent investigations, including all the 

 known German localities of Upper Oligocene beds, he has been 

 enabled to compile a complete view of the whole Foraminiferous, 

 Anthozoan, and Bryozoan fauna of the Upper Oligocene. Should 

 future researches lead to the discovery of a few more species, they 

 would only fiU up gaps, but in no way effect any important change 

 in the general view of the question. Before describing the indivi- 

 dual species he makes the following remarks : — 



1. Foraminifera. — Hitherto 142 species have been observed, with 

 two remarkable varieties. Of these only 5, which, moreover, are 

 very scarce, belong to the division with siliceous shells ; 16 species 

 have a thick calcareous shell without pores ; the great majority, 

 viz., 121 species, have a calcareous poriferous shell. 



From the table of genera it appears that the Ehabdoidese (with 

 21 species), the Cristellaridese (with 25 species), the Polymorphini- 

 dese (with 40 species), and the Rotalidese (with 19 species) are the 

 most abundant. The genera containing the greatest number of 

 species are, Cristellaria, jRohulina, Olohulina, Polymorphina, and 

 Rotalia. He then adds a list of those species which are the most 

 abundant and characteristic of the whole fauna, the more so as 

 they are almost all peculiar to the Upper Oligocene. 



