28 



THE GEOLOGICAL HISTORY OF PLANTS. 



Owen, and which were by him referred to crustaceans 

 probably resembling tAmulus, were shown by the writer, 



in 1863,* to correspond 

 precisely with those of the 

 American Limnlus {Poly- 

 phemus Occidentalis) (Fig. 

 5). I proved by experi- 

 ment with the modern ani- 

 mal that the recurring se- 

 ries of groups of markings 

 were produced by the toes 

 of the large posterior tho- 

 racic feet, the irregular 

 scratches seen in Protich- 

 nites lineatus by the ordi- 

 nary feet, and the central furrow by the tail. It was also 

 shown that when the Limulus uses its swimming-feet it 

 produces impressions of the character of those named 



Fio. 6. — Trail of a modem Mng- 

 orab, to illustrate imitations of 

 plants Bometimos named Bilo- 

 bites. 



Fig. 6.— Trail of Carboniferous crustacean (Rusiehnites Acadieus), Nova 

 Scotia, to illustrate supposed Algae. 



* " Canadian Naturalist," vol. vii. 



