64 



Description of Plate IV. 



Psammosteus Maeandrinus AG., Upper Devonian. River Aa at Wenden, 



Livland. Page 36. 

 Fig. 1. Surface of a body plate. X <> Pal. Mas. Krist Univ. 



Drepanaspis Gemundenensis SCHLUT.. Lower Devonian, Gemiinden, Germany. 



Page 31. 

 Fig. 2. Surface of body plate. X 67. Pal. Mus. Krist. Univ. 



