Plate 2. 



[After Dybowski.] 



This and the three following plates, copied from DybowsM, are about two-thirds of 

 the size as published by him. In the descriptions of these plates the generic and spe- 

 cific names are as given by Dybowski, while the horizon and locality were obtained 

 from his descriptions. Notes by the present writer are enclosed in brackets. 



Dianulites fastigiatus Eichwald. 



Fig. 1. Transverse section through middle portion of zoarium. 



2. Tangential section near surface of colony. 



3. Vertical section. 



Zone 1 [B], Reval, Pulkowa, etc. 



Dianulites petropolitanus Pander, sp. 



4. Tangential section. 



5. Vertical section. 



Zones 1 and 2 [B], various localities. 



Dianulites petropolitanus var. hexaporites Pander. 



6. Side view of zoarium, X2/3. 

 6a. Surface of zoarium, X2/3. 



Zone 1 [B], Reval, Pulkowa, Popowka. 



Dianulites apiculatus Eichwald. 



7. Tangential section cutting the basal zone of small cells. 



8. Vertical section. 



Zone 1 [B], Pulkowa, Popowka, etc. 



Dianulites rhombicus (Nicholson) . 



9. Tangential section of zoarium. 



Zone 2 [E], Wesenberg. 



Dianulites elegantulus (Fr. Schmidt). 



10. 10a. Two fragments of zoaria. i 

 106. Tangential section. 

 10c. Vertical section. 



Zone 8 [Silurian], Ohhesare-pank and Kattripank. 



Dianulites haydenii, new species. 



11. Side view of fragment, X2/3. 

 11a. Tangential section through mature zone. 

 116. Vertical section. 



Zone 2 [E], Wesenberg. 



Dianulites sulcatus, new species. 



12. Fragment of zoarium, X2/3. 

 12a. Vertical section. 

 126. Tangential section. 



Zone 2 [D], Kertel, island of Dago. 



852 



