64 



Description of Plate IV. 



Psaiiimostens Maeandrinus Ag., Upper Devonian, River Aa at Wenden, 

 Livland. Page 36. 

 Fig. 1. Surface of a body plate. X ^i- Pal- Mus. Krist Univ. 



Drepanaspis Geniundenensis Schlui.. Lower Devonian, Gemiinden, Germany. 



Page 31. 

 Fig. 2. Surface of body plate. X 6—7. Pal. Mus. Krist. Univ. 



