﻿PLATE II. 



DEVONIAN CRUSTACEA. 



Order — Merostomata. 

 Sub- Order — Eurypterida. 



Fig. 



1. Pterygotus anglicus, Ag. (natural size), from the indurated shale overlying the 



" Arbroath Paving-stone," Turin Hill range, near Forfar. One of the most entire 

 specimens obtained. See page 34. 



The dorsal surface is exposed to view; but the organs of the mouth, &c, are 

 seen impressed through the integument of the head-shield. 



Prom the Museum of James Powrie, Esq., P.G.S., Reswalhe. Forfar. 



2. Pterygotus anglicus, Agassiz. Probably about the third, or fourth body-segment of a 



very large individual, the original measuring 18 inches in breadth and 4| in 

 depth. From the Devonian of Forfarshire. See page 41. 



The original specimen is preserved in the British Museum. 



