twenhofel: expedition to the Baltic provinces. 323 



considerable number of flint concretions occur. Another quarry at 

 Pajus has an exposure of about eight feet of finely crystalline hard 

 limestone in beds up to eight inches thickness. A few poorly preserved 

 corals were the only fossils seen. These two exposures are near the 

 base of the Addifer formation, and they may belong to the Raikull 

 beds. 



At Nudi, about five miles south of Raikull, and on lower ground, is 

 an old abandoned quarry, once extensively worked. About four feet 

 of horizontal strata are exposed of which the basal two feet consist of 

 thin-bedded, gray crystalline limestone with thin shale partings, and 

 the upper two feet of thin-bedded, poorly crystalline white limestone. 

 Fossils are quite common throughout and in some layers they are very 

 abundant. Atri/pa reticularis, Pentamerus, like P. ohlongus from the 

 Clinton of New York, and Eosjnrifer radiatus are those most common. 

 These strata probably are situated quite near the base of the formation. 



The formation is excellently exposed at Kattentack near the village 

 Turpel. About four feet of thin-bedded limestones are exposed in 

 which corals are the chief fossils, these consisting of Favosites, Lyellia, 

 Halysites, and Zaphrentis. Large Pentamerus estonus and Orthis cf. 

 caUigramma Dalman are also not uncommon. 



Other localities where the strata of the formation can be seen are 

 Kerro, Fennern, and Keskfer. 



The fauna of the Addifer formation is evidently quite large, but has 

 not been well studied or collected. Important species are: — 



1. Alveolites labechi Milne Edwards. 



2. Darwinia speciosa Dybowski. 



3. Favosites gothlandicus. 



4. hisingeri Milne Edwards and Haime. 



5. Halysites catenularia. 



6. distans Eichwald. 



7. exilis Eichwald. 



8. Syringopora bifurcata Lonsdale. 



9. Vincularia megastoma. 

 10. nodulosa. 

 IL Atrypa reticularis, 



12. Eospirifer radiatus. 



13. Pentamerus estonus. 



14. Schuchertella pecten (Linne). 



15. Strophomena euglypha Dalman. 



16. Orthoceras canaliculatum Sowerby. 



