[ 53 ] 



and the tables reprefent feveral fcarce and very 

 valuable figured fojfils^ not to be feen elfe where. 



The petrifadlions or figured foflils in this work, 

 are arranged in four orders, founded on the dif- 

 ferent modes of the formation of them. 



1. Fqffiliay commonly fo called, lliells, corals, 

 animal remains, unchanged, except by being de- 

 prived more or lefs of the connefting animal 

 gluten. 



2. Redintegrata, Earthy, ftony, or chryftalline 

 foflils, formed within any cruftaceous or teftaceous 

 body, as in a mould ; thus retaining the caft, 

 without the external coat. 



3. Imprejfa, Impreflions only : as of fifhes and 

 capillary plants, or ferns, ^c. 



4. ^ranfuhfi;antiata. Perfe6t petrifafbions, in 

 which the original organic parts are perfectly filled 

 up with ftony particles, and retaining the exa6t 

 ftrudure, externally and internally, of the origi- 

 nal body. 



In 1754 was publiftied Museum Regis Adol- 

 PHI Suecorum^ ^c, in quo Animalia rariora^ imprimis 

 €t exotica ^adrupedia^ Aves^ Amphibia^ Pifces^ In- 

 fe5la^ V ermes defcribuntur et determinantur^ Latine et 

 Suetice. Fol. 1754, pp. 135. tab. 33. This fplen- 

 did volume is frequently referred to by our author 

 in his Syjlema^ on account of the figures of fo many 

 of the rarer ferpents, and fifiies, here engraven. 

 Of the former there are 48 fpecies, and of the lat- 

 ter 32 ; fpecimens of which are all preferved in 

 fpirits in the royal mufeum, in the palace of 

 WrickfdahL 



The fame which our author had now acquired 

 E 3 by 



