twenhofel: expedition to the Baltic provinces. 291 



F. A. Bather, F. R. C. Reed, Mr. John Pringle, as well as many others 

 who rendered assistance. Thanks are also due Professor Raymond for 

 the cordial comradeship and great assistance afforded during the 

 study of the Baltic sequence. Dr. R. S. Bassler has kindly read the 

 paper for which I am grateful. 



THE RUSSIAN SECTION. 



Work on the Russian section of Esthonia was begun on June 15, 

 and closed on July 17. Fossils were collected wherever it was pos- 

 sible. These have not yet reached the United States and pending 

 their arrival no detailed discussion of the correlation will be given. 



Previous icork. Many foreign geologists have studied the Estho- 

 nian sections of the Russian Ordovician and Silurian and their 

 faunas. To attempt a review of the work of these students in detail 

 is out of question, and one must be content with merely a brief refer- 

 ence to a few of those whose contributions are of greatest importance. 

 Those whose studies are perhaps of most value are : — 



Pander. Beitrage zur geognosie der russichen reiches. Niesz- 

 kowski. Versuch einer monographic der in den silm-ischen schichten 

 der Ostseeprovincen vorkommenden trilobiten. Archiv. fur naturk. 

 Liv-, Est-, und Kurlands, 1857, ser. 1, 2. Dybowski. Monographic 

 der Zoantharia Sclerodermata rugosa aus der silurformation Est- 

 lands, Nord-Livlands, und der Insel Gotland. Archiv. fur naturk., 

 Liv-, Est-, und Kurlands, 1873, ser. 1, 5. Koken. Bull. Acad. imp. 

 sci. St. Petersburg, 1897, ser. 5, 7, no. 2. Eichwald. Bull. Soc. nat. 

 Moscow, 1854, 1855. The most extensive contributor to the knowl- 

 edge of the Baltic section in Russia was F. Schmidt, who in numerous 

 papers, beginning in 1858, has described the section and its faunas.^ 

 For more than fifty years he wandered over the Russian Baltic sec- 

 tions, collecting fossils, studying the stratigraphy, and making observa- 

 tions in many fields. 



A more recent paper by Bassler ^ discusses the Ordovician section, 

 comprehensively describes the Bryozoa, and attempts a correlation 

 with American equivalents. The latest paper is by Axel Born,^ 



1 Schmidt. Untersuchungen iiber die silurische Tormation von Ehstland, Nord-Livland und 

 Oesel. Archiv. fur naturk. Liv-, Est-, und Kurlands, 1858, ser. 1, 2, p. 1-248, 465-475. 



2 Bassler. The early Paleozoic Bryozoa of the Baltic Provinces. Bvdl. 77, U. S. N. M., 191 1 . 



3 Born. Centralbl. min. geol. pal., 1913, no. 22, p. 712-720. 



