C »8j ) 
©f Mountains and Rocks, were not originally coverings 
of Animals of their refpeftive kinds, fince the very 
bruifes which they received by the weight of the Am- 
bient Matter, as it grew harder, and conftquently preft 
more heavily upon them, are ftill plainly vifible. Some 
of the Echini being robbed of their Prickles, and loof- 
ned in their Joints, which being naturally membranous, 
eafily part, being corroded by the humid [ and per- 
haps acid J fubftance in which they lay. {F), 
And whereas it may be objeded, that thefe Shells 
may grow ly little and little^ and confequently feme 
may be tenderer than others,as not being exadly formed; 
he fays he can fliew Lumps of' Stone exce/Tively hard 
full of Conchce, Turlens, Scallops and the like, where, 
within fome of them, all the parts of the Animal it felf 
may be diftindly obferved ; which is not fo very rare 
neither, but that he has feveral times obferved it. This, 
fays he, puts the Original of thefe Shells out of doubt ; 
fince they hapned to be clofed before the liquid Mud 
could get in and corrode the included Animal, and af- 
terwards harden into the exafl: form which its Matrice 
muft of necelTity give it: Whereas the others being 
firft filled with Mud, which hardned into a flony con- 
fiftenceafcer the Animal was quite wafled, gave occafiop 
to ftme Perfons who had not feeagreat varieties of Shells 
and formed Stones of that fart,to doubt of their Original, 
.He reafons alfo from the feveral Lamellce, of which 
thefe Land-fhells are compofed, which are coated over 
one another in fuch a manner, that they may be parted 
into very thin and fabtile Plates, fuch as Sea-fliells of 
that kind are made up of 
But it was obje(£led, that in thofe Beds where thefe. 
Shells are found, generally fpeaking, mofi of one fort 
are found together, from whence it has been concluded 
that, they are firft formed in thofe .Beds where they are 
found. Whereas he pretends that this proceeds only 
frcm i 
