﻿PLATE I. 



DEVONIAN CRUSTACEA. 



Order — Merostomata. 



Sub- Order — Eurypterida . 



Fig. 



1. An almost entire body of Pterygotus anglicus, Agassiz, the original specimen 



measuring 23 inches in length, preserved on a slab of grey micaceous sandstone 

 from Turin Hill range, Forfarshire. Two thirds natural size. See page 34. 



2. A detached head of Pterygotus anglicus, Ag., figured of the natural size, showing the 



marginal eyes (e, e). See page 36. "From the Old Red Sandstone, Eorfarshire. 



2a. A small portion of the surface of the head, enlarged. 



3. Basal joint of the left maxilhped of Pterygotus anglicus, Ag. (natural size), from the 



Old Reel Sandstone, Forfarshire. See page 38. 



4. Pterygotus minor, H. Woodw. (natural size), from the indurated shale overlying the 



" Arbroath Pavmg-stone," Farnell, Forfarshire. See page 35. 



The above specimens are all from the Museum of James Powrie, Esq., F.G.S., 

 Reswallie. Forfar. 



