TwTr\-HOFKL- — ExpeditioD to the Baltic Provinces. 



PLATE 3. 



Fig. 1. — Contact between the Jorden Schicht and the Peniamerus borealis 

 banks at Jorden. Esthonia. The t\"pe-section. 



The hammer is on the hne of division. The spots in the upp>er 

 strata are the shells and molds of Pcniamerus borealis. 

 Fig. 2. — Quarni^ face in the Raikull formation at the type-locality in Esthonia. 



