292 FOSSIL CRUSTACEANS. 



SECTION I. 



First Class of Articulated Animals, 



FOSSIL ANNELIDANS. 



However numerous may have been the ancient species 

 of Annelidans without a shelly covering, naked worms of 

 this class can have left but slight traces of their existence, 

 except the holes they perforated, and the little accumulations 

 of sand or mud cast up at the orifice of these perforations ; 

 in a preceding chapter* we have noticed examples of this 

 kind. We have also abundant evidence of the early and 

 continued prevalence of that order of Annelidans, which 

 formed shelly calcareous tubes, in the occurrence of fossil 

 Serpulae in nearly all formations, from the Transition periods 

 to the present time. 



SECTION II. 



Second Class of Articulated Animals. 



FOSSIL CRUSTACEANS. 



The history of fossil Crustaceans has been hitherto almost 

 untouched by Palseontologists, and their relations to the ex- 

 isting Genera of this great Class of the Animal Kingdom 

 are to olittle known to admit of' discussion in this place. 



See note at pages 198 — 199. 



