202 
SERPULA antiquata. 
TAB. DXCVIII.—fig. 4. 
Spec. Cuar. Cylindrical, partly attached by an 
expanded surface; surface uneven, with trans- 
verse irregular rings. 
Tue diameter is three or four lines, very slowly decreas- 
ing; the edge of the aperture is obtuse. 
Casts in silex marked with the small rings peculiar to 
that substance, are common in the Greensand of Wilt- 
shire. 
A small portion imbedded in clay, found in Kast Weare 
Bay near Folkstone by H. H. Goodhall, Esq., is added 
to the figures, as it appears to be the same species. 
(ae ee == 
SERPULA tenuis. 
TAB. DXCVIII—fig. 5. 
Spec. Cuar. Cylindrical, with a minute carina upon 
the back, and a few distant sharp rings; shell 
thin. 
A very small species occurring in little groups, and 
single individuals fixed by an expanded part of the sur- 
face to each other or to other substances. 
This isthe Serpula found in the freshwater deposit of the 
Hampshire Coast described by Charles Lyell, Esq., in the 
Second Series of the Geo]. Trans. vol. ii. part II. p. 289. 
it occurs inthe White Sand in Hordwell Cliff along with 
Mya plana, Mytilus Brardii, &c. See Min. Con. tab. 532. 
It also was observed along with Cyclas pulcher opposite 
Hampstead Cliff in the Isle of Wight, and is noticed on 
page 51 of the present volume. We have not ascertained 
that it is attached to the shells it accompanies. 
The lower figures are magnified. 
