£ 59 3 
they are found. Some of the Specimens have their 
Surface fmooth and even, whilft in others it is co¬ 
vered with a Mixture of Excrefcences and Cavities, 
or diverfified with beautiful and regularly difpofed 
Lines: their Size and Form is various, according 
to their different Kinds. The Spines of thefe foflil 
Shells tire generally found near them, and of the 
fame Subftance : They abound moft in Chalk Pits. 
The Lapis Judaic us, found in Judea , is of this Clafs: 
They are often called Olive Stones, from their 
bearing in Figure fome Refemblance to an Olive ; 
they are very elegantly marked, and the Surface of 
them with Regularity covered by a great Number 
of Tubercles. 
Belemnites , vulgarly called Thunderbolts. They 
are compofed of feveral Crufts of Stone encircling 
each other, of a conical Form, and various Sizes. 
They are fuppofed to be originally either a Part of 
fome Sea Production, or a Stone formed in the 
Cavity of fome Worm Shell, which being of a ten¬ 
der and brittle Nature, has perifhed, after giving 
its Form to the Stone. They are very frequently 
found in many Parts of England j and the common 
People have a Notion that they are always to be 
ipet with after a Thunder Scorm. They are often 
enclofed in, or adhere to other Stones, and are moft 
frequently amonglt Gravel, or in Clay ; they abound 
in Glocefierjhire , and are frequently found near De~ 
dington in Oxfordshire , where they fometim.s contain 
the Silver Marchafice. 
Aiieria^ Star (tones. Thefe are fmall (hort an¬ 
gular or ftilca^ed Columns, between one and two 
Inches long, and feldom above fa third of an Inch 
in Diameter: they are compofed of feveral regular 
Joints ; when feparated, each refembles a radiated 
'Star i fume have four, others five Rays or Points, 
either 
