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. 1. It has received the name /éerygotus (or wing-eared) 
from certain fanciful resemblances pointed out by the quarrymen. 
Fic. 1.—Pterygotus anglicus. (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 
