Page:The Habitat of the Eurypterida.djvu/175

Rh only in the Hagshaw Hills to the chocolate-colored sandstones at the top, but the only bed of particular interest in the present discussion is the fish band which has been found in several places. In the Monk's Water, about three-quarters of a mile south of Monkshead, the following fossils are reported from this band:


 * Eurypterus, small sp.
 * Scorpion
 * Ceratiocaris ?
 * Thelodus scoticus (Traq.)
 * Birkenia elegans (Traq.)
 * Lanarkia spinosa (Traq.)
 * L. spinosa (Traq.)
 * L. horrida (Traq.)
 * Lasanius problematicus (Traq.)
 * Sponge?

. The closing stages of the Siluric in northwestern Europe were marked by an expansion of the continental areas and an accompanying widespread retreat of the sea which left all of Great Britain except the southwestern portion of Devonshire, all of Scandinavia, Finland, and the northern borders of Germany dry land. Over the region thus exposed was deposited a great series of conglomerates, sandstones, and shales, dominantly red in color, and reaching a thickness of many thousands of feet, the formations being collectively called the Old Red sandstone facies of the Devonic. It was early recognized that the conditions of sedimentation under which these deposits accumulated were essentially different from those under which the marine Devonic limestones of Russia, western Europe, and extreme southwest England were formed. Not only did the tremendous thickness of the beds attract attention, but the coarseness and prevailing red color of the deposits, and particularly the almost entire absence of organic remains, caused considerable speculation on the part of continental as well as British geologists on the origin of this remarkable series. In the early part of the last century the suggestion was made by Dr. John Fleming that the Old Red might have been deposited in lakes. This theory was eagerly taken up first by Godwin-Austen (6) in 1855 and by a host of later writers, each one of whom contributed some bit of