LAUREXTIAX AXD EARLY PAUBOZOIC. 



rites, from the same beds which afford Pro- 

 The principal difference between Protichnites 

 their modern representatives is that the latter have 

 ro lateral furrows 

 luced by the 

 les of the cara- 

 pace, which are 

 wanting in the for- 



I subsequently 

 the same 

 planation to sev- 

 eral other ancient 



now 



the gener- 

 name Bttobitc* 

 6 and 7).* 



tubercu- 

 impressions 

 wn as Phyma- 

 and Cavi- 

 ties may, as Zefl- 



by the bur- 

 rof themole- 



? and fine examples occurring in the Clinton f orma- 

 L of Canada are probably the work of Crustacea. It is 

 however, that some of die later forms referred 

 genera, are really Algae related to Caultrpa, or 

 ; of Conifers of the genus BrachyphyUum. 

 and Plamditts are tracks and borrows of 

 with or without marks of setae, and some of the 



<ifi?^ 



Aae are mot trae plate tat ljr 



ihis is cf ihe : 



