NATURAL HISTORY OF SELBORNE. 



shells themselves in high preservation. This bivalve is only known 

 to inhabit the Indian ocean, where it fixes itself to a zoophyte, 

 known by the name Gorgonia. The curious foldings of the suture 

 the one into the other, the alternate flutings or grooves, and the 

 curved form of my specimen being much easier expressed by the 

 pencil than by words, I have caused it to be drawn and engraved.* 



Cornua Ammonis are very common about this village. As we 

 were cutting an inclining path up the Hanger, the labourers found 

 them frequently on that steep, just under the soil, in the chalk, and 

 of a considerable size. In the lane above Well-head, in the way to 

 Emshot, they abound in the bank in a darkish sort of marl ; and 

 are usually very small and soft : but in Clay' s Pond, a little farther 

 on, at the end of the pit, where the soil is dug out for manure, I 

 have occasionally observed them of large dimensions, perhaps 

 fourteen or sixteen inches in diameter. But as these did not consist 

 of firm stone, but were formed of a kind of .terra lapidosa, or hard- 

 ened clay, as soon as they were exposed to the rains and frost they 

 mouldered away. These seemed as if they were a very recent pro- 

 duction. In the chalk-pit, at the north-west end of the Hanger, 

 large nautili are sometimes observed. 



In the very thickest strata of our freestone, and at considerable 

 depths, well-diggers often find large scallops or pectines, having 

 both shells deeply striated, and ridged and furrowed alternately. 

 They are highly impregnated with, if not wholly composed of, the 

 stone of the quarry. 



* Our author was mistaken in referring this fossil to the Mytilus crista galliot Linnaeus. 

 Mr. Bennet, who has explained the subject in a note to his edition of Selborne, refers it 

 to the Ostrca carinata of Lamarck, a species peculiar to the green-sand formation, upon 

 which the village of Selborne is built, and which from its white colour would be easily 

 confounded with the chalk, especially at a time when geology was much less ; ttended to 

 than at present. 



