142 THE HABITAT OF THE EURYPTERIDA 



the eurypterid fauna which was to become world renowned. 9 In his 

 report on this region he says: "The gray, compact dolomite of Root- 

 zikull, on the west coast of Oesel, reveals the thin membraneous tests 

 of Eurypterus remipes Dekay [= E. fischeri Eichwald] entirely un- 

 changed, not only in their chemical composition, as pure chitin, like 

 that found in the shells of living Crustacea, but also in their whole 

 internal microscopic structure and preserved with their original 

 brown color peculiar to living animals" (Schrenk, 254, 35). 



In the following year, 1853, Eichwald apparently not knowing of 

 Schrenk's discoveries visited the same provinces and islands and on 

 Oesel two versts from Rootzikull in the village of Wita he, too, came 

 upon the eurypterid horizon whose assemblage of organisms sur- 

 prised him not a little, for he says: "I was astonished to find a vast 

 multitude of Eurypterus remipes [E. fischeri (Eichwald)] in this lime- 

 stone" (Eichwald, 57, 49). By his collections he added much to the 

 knowledge of the rest of the fauna, but I shall not at this point give 

 the species which he found, since later workers added materially to 

 the faunal lists. During that same summer Schmidt and Harder 

 accompanied Eichwald to Wita and other nearby localities where 

 eurypterids were found; in 1856 Schmidt returned again to Oesel and 

 the following year Niezkowski, Schmidt and Czekanowski made large 

 collections at the best localities. Again in 1858 Schmidt revisited the 

 island, and as the result of these extensive collections and field studies 

 several important papers were brought out. By far the most com- 

 plete and comprehensive were those by Schmidt, the first published 

 in 1858 entitled " Untersuchungen ueber die Silurische Formation 

 von Ehstland, Nord-Livland, and Oesel" 10 embodies the first detailed 

 stratigraphic and palaeontologic discussion of these regions. Schmidt 

 gave the first geologic map of the region and the zonal subdivision 

 of the "Silurian" which is still used in the east Baltic provinces. In 

 the following year Schmidt published a short notice on some further 

 discoveries in Oesel (243). His most important paper on this island 

 appeared a number of years later in 1883 as one of the "Miscellania 

 Silurica" in the Memoires de l'Academie Imperiale des Sciences de 

 Saint-Petersbourg, entitled "Die Crustaceenfauna der Eurypteren- 



9 He had been led to look for this fauna because he had noticed in the Dorpat Museum certain 

 fine specimens which had been sent in from Arensburg, southeast Oesel, by Oberlehrer Werner, who 

 had knocked them out of loose blocks of building stone. (Xieszkowski, 197, p. 303.) 



10 It is true that pioneer work on the mainland had been done by M. v. Engelhardt and E. 

 Ulprecht. the results being embodied in a paper entitled "Umrisz der Felsstructur Ehstlands und Liv- 

 lands" in Karsten's Archivflir Min. Geogn. Bergbau u. Hiittenk. for 1830, but the paper does not touch 

 on Oesel. Similarly in the Geology of Russia by Murchison, de Verneuil and Keyserling Oesel is 

 passed over in a few sentences. 



