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Upon a minute examination of its external surface, a spongeous, or 
rather porous structure, is discoverable : some of the pores appearing 
to be the result of a peculiar reticulated texture ; whilst others, of ra- 
ther an oval form, may be supposed to be the openings of the rami- 
fying tubuli, already noticed. The examination of its internal sur- 
face is prevented by a friable rnatter, which appears to be partly cal- 
careous and partly silicious, with which its cavity is nearly filled. A 
portion of the posterior part is covered with this same matter, which 
seems to have invested the whole fossil, and appears rather to have been 
a covering peculiar to the animal than merely the matrix in which it 
had lain. This fossil resembles, in its composition, several of the French 
and Swiss alcyonic fossils, already mentioned, in being an intermixture 
of silicious and calcareous earth : the former having possessed the animal 
substance itself, and the latter the interstices. 
Small fragments of this kind of fossil had been long discovered, 
whilst digging or ploughing in the Vale of Pewsey : but their forms 
were so indeterminate and various, as to have led to the most vague 
and fanciful conjectures respecting their original nature. By some 
they were imagined to be portions of petrified wood, and by others 
to be fragments of bones ; but Mr. Townsend, who had met with them 
in his own garden, collected numerous specimens, and in consequence 
of his extensive knowledge in natural history, soon ascertained their 
origin, and determined that they were the mineralized remains of some 
zoophyte of the former world. 
According to Mr. Townsend's obliging information, these remains of 
zoophytes are found immediately under the chalk, in a dark green sili- 
cious sand, which contains many prism of quartz crystals ; the colour 
being derived from the intermixture of an oxide of iron. In the same 
green sand, nautilites are found of a foot or fourteen inches diameter ; 
and on digging deeper, similar bodies to those existing in the green 
sand are found, approaching to an agatized state. 
The farther I advance in my labours, the more reason I find for con- 
