26 



EXTINCT MONSTERS. 



wood-lice of the present day ; and the record of the rocks tells 

 us plainly that creatures built upon this plan have flourished ever 

 since. We mention this because they are related to the king- 

 crabs of the present day, and therefore to the huge old-fashioned 

 sea-scorpions we are now considering. 



The best-known and largest of these creatures is represented 

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

 from certain fanciful resemblances pointed out by the quarrymen. 



Fig. I. — Pterygotus aii^Hctis. (After Woodward.) 

 I. Upper side. 2. Under side. 

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

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

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

 Arbroath paving-stone. The quarrymen, in the course of their 

 work, came upon and dug out large pieces of the fossilised remains 



