222 



separated from any other ancient gravel in which bones or shells have 

 not been discovered. 



The loess at Basle crovi^ns the summit, and is found on the sloping 

 sides of several lovi^ hills which bound the valley of the Rhine ; but it 

 is best seen one or two miles to the south of the town, in the hills 

 called Bruder Holz, where it rests upon nearly horizontal beds of 

 raolasse. The loess has here an elevation of more than 1100 feet 

 above the sea ; for it is found in places which are more than 300 feet 

 above the Rhine at Basle, according to the measurement of Prof. 

 Merian, who has also determined that the Rhine at Basle is about 

 760 French feet (809 English) above the level of the sea. 



The principal section examined by Mr. Lyell is near the northern 

 extremity of the Bruder Holz below the church of the village of Bin- 

 ningen. The loess in this place is of its usual yellowish grey colour, 

 and is filled with terrestrial and freshwater shells. The lower beds al- 

 ternate with strata of sand and gravel, and in one of the loamy strata 

 of this part of the series, he found the vertebree offish, together with 

 the following loess shells : Succinea ohlonga, Pupa muscorum, Clau- 

 siliaparvula, Helix cellaria, H.plebeium, H. arbustorum, H. rotundata, 

 Bulimus lubricus, and a small Planorbis, all recent shells. 



The vertebrae, M. Agassiz says, belong decidedly to the Squalidas 

 or shark family, perhaps to the genus Lamna. The one is a caudal 

 and the other an abdominal vertebra, each about a quarter of an inch 

 in diameter. They are in such a state of preservation, and of such a 

 colour as might be expected in bones preserved in loess, and as they 

 were in a bed of fine loam in which there were no extraneous fossils,, 

 Hor any fragments of rock washed out of other formations, there is 

 no reason to suspect that they could have been derived from the ter- 

 tiary molasse ; and M. Agassiz also states that he has seen nothing 

 like them in the molasse of Switzerland. It may seem very extraor- 

 dinary that the first remains of fossil fish obtained from this freshwater 

 silt should belong to a marine genus, but M. Agassiz has informed 

 Mr. Lyell that both in the Senegal and the Amazon certain species 

 of the shark and skate families (Squalus and Raia, Linn.) have been 

 known to ascend to the distance of several hundred miles from the 

 ocean, and analogous facts are referred to in Margrave and Piso's 

 Natural History of India. 



A notice on the occurrences of selenite in the sands of the plastic 

 clay at Bishopstone near Heme Bay, by William Richardson, Esq., 

 F.G.S., was lastly read. 



The perpendicular cliff in which the selenite occurs is about a hun- 

 dred feet in height, and consists of the following strata : 

 Vegetable mould. 



Reddish marl or brick earth 5 feet. 



London clay 20 to 30 — 



Sand and sandstone 60 — 



The selenite is found in the sand, which, as far as the author could 

 determine, contains no iron pyrites or lime except in a few well-de- 

 fined lines of testaceous remains. The superjacent clay abounds in 



