SEA-SCORPIONS 51 



that they are related to scorpions, and for this reason we call 

 them Sea-scorpions. (See Plate II.) 



The Crustacea are a very ancient race, as well as a flourishing 

 one; some very old rocks containing undoubted fossils namely, 

 certain slates found in Wales and the Lake District tell us of a 



FIG. 6. Pterygotiis anglicus, six feet long. 

 1. Upper side. 2. Under side. (After H. Woodward.) 



time when shallow seas swarmed with little articulate animals 

 known as trilobites. 



The best-known and largest of the Sea-scorpions is represented 

 in Fig. 6. It has received the name Pterygotus (or wing-eared), 

 from certain fanciful resemblances pointed out by the quarrymen. 

 It was first discovered, along with others of its kind, by Hugh 

 Miller, at Carmylie in Forfarshire, in a certain part of the Old 

 Eed Sandstone (see Table of Strata, Appendix I.) known as the 



