Page:The Habitat of the Eurypterida.djvu/30

 considerable amount of structureless carbonaceous matter distributed in thin layers" (Laurie, 145, 151). The only other fossil which Malcolm Laurie found in the rock at the time of his first discovery was Dictyocaris ramsayi, but since then Peach and Horne have made a large collection of other types. In 1898 Laurie added some new discoveries from Gutterford Burn, and among these the one specimen of a scorpion, much crushed and lying imbedded in the carbonaceous matter. In the Pentland Hills the Wenlock formation is a yellowish sandstone and conglomerate, showing cross-bedding and in some places ripple marks, and is exposed in several inliers in the Old Red Sandstone, later formations having been eroded. Extensive collections have been made here by Henderson, Brown and Laurie, the latter describing a number of new species. One of the best sections is seen along Gutterford Burn, a tributary of the Esk, where the following specimens have been collected, the determinations having been made by Laurie.
 * Bembicosoma pomphicus Laurie.
 * Stylonurus (Drepanopterus) pentlandicus (Laurie).
 * S. (Drepanopterus) bembicoides (Laurie).
 * S. (Drepanopterus) lobatus (Laurie).
 * Eurypterus conicus Laurie.
 * E. minor Laurie.
 * Eusarcus scoticus (Laurie).
 * Eurypterus 3 sp. undet.
 * Stylonurus elegans Laurie.
 * S. macrophthalmus Laurie.
 * S. ornatus Laurie.
 * Slimonia dubia Laurie.
 * Dictyocaris ramsayi Salter.
 * Palaeophonus loudonensis Laurie.

Upper Siluric or Ludlow. The Ludlow of England has yielded eight species of eurypterids all in a most fragmentary condition, making it difficult to determine forms accurately. They all come from the Ludlow outcrops in Shropshire and Herefordshire. From the Aymestry limestone there are some remains which have been doubtfully referred to Pterygotus problematicus. This same species appears again and again throughout the remainder of the Siluric, being rare in the Upper Ludlow group, but becoming more common towards the top of the Temeside group in the Ludlow district. Eurypterus acuminatus Salt. and E. linearis are rare in the Upper Ludlow, the former