PLATE XXXIII. 



AURELIA PLAVIDULA (p. 5). 



Trails produced by drawing the oral arms of the medusa over the surface of soft plaster, the 

 arms being drawn in about the same manner as they would have been if drifted along by a current 

 in shallow water near the shore. 



The resemblance of these trails to those of specimens of Eophyton and other trails that have 

 been referred to Alga3 and other fossil plant remains, is very striking. Compare with figures of 

 Pis. XXXII, XXXV. 



170 



