Ill 



и. Psammobia sp.? 



Plate III, fig. 11. 



Some shells found in the Cyrena-beå I consider, though 

 somewhat doubtfully, to belong to the genus Psammobia. 



The shell is oval, very oblong and rather flat. The umbo 

 is only slightly prominent and is situated at about the middle 

 of the shell. The valves seem to gape both at the front and 

 at the back. On the surface concentric growth lines are seen; 

 at the ends the lines are coarser and here form a moire-like 

 ornamentation. 



The species in question resembles in form somewhat Ps. 

 plana Desh. but it is in too bad a state of preservation for 

 more definite determination. 



Height about 9 mm., length about 18 mm. 



The Cyrena-bed: 4 specimens. 



12. Donax sp. 



Plate HI, fig. 13. 



In the Cyrena-bed has been found a single shell, which 

 probably belongs to a species of the genus Donax. The shell 

 is thin and flat, oblong-triangular, very inequilateral; narrowing 

 in front, but yet rounded; at the posterior regions short and 

 rounded. The surface is covered by irregular growth lines. 

 — As I have not been able to examine the hinge and the 

 course of the palliai line a more exact determination is 

 impossible. 



Height about 20 mm., length about 30 mm. 



The Cyrena-bed: 1 specimen. 



13. Teredo sp. 



Some pieces of fossil wood of some foliferous tree is quite 

 perforated by Teredos. The borings are now filled with sand- 

 stone or calcite. The perforations are more or less curved. 



