376 GEOLOGY OF SELBORNE. 



It may be here observed that the hollow lane between 

 Hartley and Selborne, in some parts nearly twenty feet deep, 

 with almost perpendicular sides, is cut by the joint action of 

 water and the wear of traffic through some of the upper beds 

 of the Malm rock. These beds consist of alternations of hard 

 blue argillaceous ragstone, one or two feet thick, and of softer 

 ones of sandstone, called Firestone, four or five feet thick. 

 The lower beds of the Upper Greensand are of a marly 

 character. 



A few general observations on the fossils from the beds in 

 question may here be added. The Chalk in the vicinity of 

 Selborne is so little exposed that I have obtained few fossils 

 from it. Gilbert White speaks of large " Cornua Ammonis " 

 being found when cutting an inclined path up the Hanger. 

 These must have been in the Lower Chalk, and in a bed cor- 

 responding with one near Alton, in which I have found large 

 Ammonites of several species, the largest, in the museum of 

 that town, measuring 27 inches in diameter. With these 

 occur smaller Ammonites and small Nautili. The large 

 Nautili mentioned by Gilbert White as occurring at the north- 

 west end of the Hanger belong to the Chalk marl. 



These Nautili of the marl (N. elegans) are the largest species 

 found above the chloritic bed. The most abundant fossil in 

 the Chalk marl is the A. varians, and the most characteristic, 

 as it is small and scarce in the other beds. In the side of the 

 lane turning up the hill from Fisher's Buildings I procured 

 two species of Turrilite, costatus and tuberculatus, and one of 

 Micraster. I have several specimens of the " Mytilus Crista- 

 galli" (Ostrea carinata), figured in the ' Natural History of 

 Selborne,' which I did not find in situ; but I believe they be- 

 long to the Chalk marl. 



The chloritic marl is a sandy slightly coherent bed, clearly 

 distinguished by its black and green particles. After heavy 

 rains these may be seen spread over the bottom of the little 

 stream flowing from Well Head. This bed may still be seen 

 in the "lane above Well Head in the way to Emshot," 

 where Gilbert White describes it as a " darkish sort of marl." 

 He speaks of the soil it produces the "black malm " as a 



