268 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 22, 



Spessart, or the River Kinzig in like manner might have brought 

 them down from the Fichtel Gebirge. 



5. Mternating beds of sand and hmestone ; the sand is in some 

 places slightly ferruginous, and contains fragments of shells ; the 

 hmestone occasionally alternates with sandy marl, containing a small 

 liittorinella ; it is a kind of junction-bed with No. 4, into which it 

 sometimes passes. The singular small round bodies, described by 

 some naturalists as snakes'-eggs*, have been found in this part of the 

 section. 



This bed brings us to the level of the little town of Hochstadt, 

 built on the slope of the hill. Many small pits have been opened on 

 the ground above the town, by means of which the section can be 

 tolerably well traced upwards. Littorinellce abound in most of these 

 beds, but the Helices are less frequent than below. 



6. The only characteristic horizon which I observed in this upper 

 succession of limestone beds, more or less compact or arenaceous, is a 

 band nearly a foot thick, containing Mytilus Faujasii. 



7. (B. 5.) The highest bed in this section which I bad an oppor- 

 tunity of observing consists of blue clay, in which the small Cyrena 

 Faujasii and a Cerithium, probably C. cinctum, are tolerably abun- 

 dant. 



IV. Littorinella-limestone. (No. 5 of the German list, page 260.) 



One of the chief localities for observing the various beds of this 

 portion of the Mayence basin, which in a general sense may be con- 

 sidered as the upper portion of the brackish-water limestone forma- 

 tion, is the district lying between the towns of Hochheim and Flors- 

 heim on the Maine. The numerous quarries opened on the slope of 

 these hills have produced an abundant harvest to the palseontological 

 inquirer, and have, in connection with the railway cuttings, brought 

 to light a great variety of new forms of land-shells of the genera 

 Helix, Pupa, Bulimus, Clausilia, and Cyclostoma. The valley of the 

 Miihl-thal, leading from Biebrich to Wiesbaden, is a portion of this 

 formation, and appears to represent its upper beds. It is moreover 

 remarkable for containing, in addition to the molluscs found near 

 Hochheim, a considerable number of freshwater shells. 



I visited the Hochheim beds in company with Mr. Austen. The 

 best section we obtained was at the eastern end of the line of quarries 

 near Florsheim, at a place called the Ziegel Hiitte. The section of 

 the lower part of this group here is remarkable for presenting on the 

 same horizon two distinct series of beds, apparently without a fault 

 (see fig. 10). The mass of rock in the centre consists of hard concre- 

 tionary mammillated calc-sinter, made up of minute hollow stems, the 

 interstices between which are often filled with fine sand. It looks as 

 if the calcareous matter, the produce of springs highly charged with 

 carbonate of lime, had been deposited on masses of jNIosses or Con- 

 fervcB, an appearance not uncommon in other parts of the formation. 

 I particularly noticed it near Diu'ckheim, where the limestone also 



* Quart. Journ. Geol. Soc. vol. vi. part 2. Misccll. p. 12. 



