64 



Description of Plate IV. 



Psammosteus Maeandrinus Ac., Upper Devonian, River Au at Wendeii, 



Livland. Page 36. 

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



Drepanaspis Gemundenensis SCHI,UT.. Lower Devonian, Gemiinden, Germany. 



Page 31. 

 Fig. 2, Surface of body plate. X 07. Pal. Mus. Krist. Univ. 



