378 Scientific Intelligence. — Geology. 



disintegrated condition. It acts principally on the carbonates 

 of iron and manganese : it converts them into bicarbonates, and 

 thus renders them soluble in water. 



7. Fossil Trees in an erect jjosition. — In geological writings 

 mention is frequently made of fossil trees being found in strata, 

 in their natural erect position, and therefore still on the spot 

 where they grew. We have always objected to this opinion, 

 and maintained that those fossil trees only, in which the roots 

 are spread through a soil different from that surrounding the 

 trunk and branches, are to be considered as in their natural 

 and unaltered position. In the sandstone quarries around Edin- 

 burgh, fossil trees are found in all positions, from the upright 

 to the horizontal, and enveloped in the same general mass. 

 These, therefore, are trees which have been moved from their 

 original situation and position. 



8, Crustacites and Cidarites in Mountain-Limestone. — Count 

 Munster enumerates in Leonhard's Jahrbuch, Erst. Jahrg. 1. 

 Heft. p. 60. et seq., fourteen species of the genus Cytherina, he 

 found in the tertiary sand-marl of Astrupp near Osnabruck. 

 They were collected from the interior of the Terebratula gran- 

 dis of Blumenbach, the Terebratula gigantea of Schlotheim. 

 Some of these species occur also in the ferruginous sand of the 

 Welhelmshohe at Cassel, in the calcaire grossiere at Paris, Bor- 

 deaux, Dax, Turin, and particularly at CastelParquato. Be- 

 sides these he also found eight species, but different from those 

 already mentioned, in the transition limestone at Regnitzlosau 

 near Hoff. These eight species, says Count Munster, " occur 

 in the upper beds of the transition limestone, called Mountain- 

 Limestone. The bed in which they occur is interesting in a 

 geognostical point of view. There follows immediately to the 

 transition limestone, abounding in species of orthoceratite, nav- 

 tilite, planidite, &c., the newer transition limestone, or the so 

 named IMountain-limestone, distinguished by the great number 

 and the many species of prodnctus, fossils which are character- 

 istic for the mountain-limestone and magnesian limestone (zech- 

 stein), but which here never occur in the true transition lime- 

 stone." In the midst of this mountain -limestone there occurs a 

 mai'ly bed, having an oolitic character, which oolite structure is 

 occasioned by numberless remains of organic bodies, of which 



