88 Mr. Lyell on a recent Formation of 



II. Marl near Rornsey in Hampshire. 



The meadows near Greatbridge, about a mile north of Romsey in Hamp- 

 shire^ afford the only locality in England where I have as yet seen shell-marl. 

 It has been applied there to agriculture for many years with advantage. It 

 occupies an alluvial tract in the valley of denudation through which the river 

 Test flowSj traversing the plastic clay formation, near the northern confines 

 of the tertiary basin of Hampshire and the Isle of Wight. The following is a 

 section of one of the above-mentioned deposits in Ashley Meads, beginning at 

 the top. 



Thickness. 



1. Alluvial clay unmixed with marl from 1 to 2 feet 



2. Shell. marl provincially termed " ma^m " 2 — 6 



3. Peat of various thickness, sometimes 6 



4. Clay and gravel (diluvium ? ) 



The chief substance of the marl consists frequently of shells ; sometimes, 

 however, about one half of it is a calcareous matter, which often forms concre- 

 tionary balls of some solidity ; these however fall to pieces immediately upon 

 exposure to the air and frost. These concretions bear no resemblance to the 

 rock-marl of the Bakie. They are never compact, but of a loose texture and 

 brownish yellow colour; they contain some iron. These and all the accom- 

 panying marls when heated afford a considerable quantity of ammonia, with a 

 smell of burnt animal matter. I am obliged to J. E. Gray, Esq., F.G.S., of the 

 British Museum, for the names of the following shells found in this marl. 



Names of Montagu. Names of Lamarck. 



1. Helix putris Succinea putris. 



2. arbustorum Helix arbustorum. 



3. hortensis hortensis. 



4. nemoralis nemoralis. 



5. carinata Planorbis carinatus. 



6. complanata complanatus. 



7. contorta contortus. 



8. alba albus. 



9. Bulla fontinalis Physa fontinalis. 



10. Helix peregra Lymnea peregra. 



11. fragilis stagnalis (var.) 



12. auricularia ■ auricularia. 



13. palustris palustris. 



14. ovata — __ ovata. 



the only part that had suffered injury. This relict is not without its value to the Geologist, as well 

 as to the Antiquarian ; since it shows that some part even of the peat, which overlies all the marl, 

 is of a date anterior to the historical records of the country. 



