( 729 ) 
aChcolour'd-grifty Glay, whiehis the evident mat erialcaufc of 
it^it being found in a bed of the fame, I eafily picktout the 
Clay with a Needle, fo that 'tis now all hollow ; the fhell-like 
andfparryfubftance being fcarceas thick as a Half-crown. 1 
muft own the knowledge of its being a radix to Mr, Lifter's hint, 
though I have jigrkoU by me, but did not well raind him ; and 
becaufe the perfetS radix was fmooth on the top, and many o- 
ther pieces of radix's which I have by me, they did not well in- 
dicate the thipg, though upon a review I find one of themwi:h 
fmall rays there.I have a great many of the Tetragonal, Pentago- 
nal and Hexagonal Plates, with concavities, convexities ; thm, 
ftnooth,and indented edges ; little round knots on the convex 
part^others being only fcabrous, others fmooth, as I find many 
large pieces of the Radix's are. The fides of fome are very un- 
equal; in fliort,they agree in all things with Mr, Lijler's defcrip- 
tions. I have one fcxangular Place very pretty, whofe convex 
part has onit a ftar confifting of fix Emboft rays, which ftoot 
from the center diredily to the middle part of the fides betwixt 
the Angles,and betwixt every two rays there grows a little (iud 
after a very elegant manner. 
5. To give an account of the /^/4^^ of their birth (though 
hinted before) I may now fay this ; I find the trochites fticking 
to rake-mold ftones, and in the crannies of Rocks at all depths, 
from the grafs to 20 fathom ; and doubtlefs there are of them 
deeper : But I find them moft plenteoufly in certain beds of an 
aflicolour'd-grifty Clay , and particularly atone place within 
a yard or two of the grafs. I found here a fruit with them like 
a lapu JudaicMsCthoagh fomewhatdefac*d)ifnot a fpecies there- 
of ; its about the bignefs of an Acorn, with ridges and furrows 
running the long way ; it differs from thofe defcrib'd by Mn 
Li/leri^. I I© ;^r/?,that this is not bigger,but rather lefs in the 
middle than at the ends; and fecondly ^ that its ridges are not 
knotted or purl'd. It is in fubftance a whitifli opaque fpar like 
the trochites^ though fas lAx.LiJler fays) fome Trochites are of a 
dark-colour'd fpar;and I find fome of a white cawky fubftance, 
• and fome have a tinflure of red 5 but thefe differences proceed 
from the Glay of which they are made; for^thoughanafbcolour 
be the chief init,yet there are fome veins of red in it , fome of 
white,fomeof a light. blew, fotne of a dark-blew &c; which 
caufe thefe varieties in the ftones. I find fome Trochites and En- 
5 C 2 trocbi 
