PLATE XXI. 



DEVONIAN AND SILURIAN CRUSTACEA. 



Order — Merostomata. 



Sub-Order — Eurypterida. 

 Fig. 



1. Stylonurus Powriei, H. Woodw., nat. size. 



Old Red Sandstone; Turin Hill Range, near Pitscandly, Forfarshire. (P. L2:2.) 

 From the Collection of James Powrie, Esq., F.G.S., Reswallie. 



2. Stylonurus Powriei ? two detached swimming feet of large size, probably belonging 



to this species. (P. 123.) 



Upper Silurian ; Lesmahagow, Lanarkshire. 



From the Collection of James Powrie, Esq., F.G.S. 



3. Sty Ion ur us megalops, Salter, sp. Head-shield, nat. size. (P. 124.) 



3 a. „ ,, part of the head magnified, showing the granular surface. 



From the Collection of Robert Lightbody, Esq., F.G.S. , Ludlow. 



4. Stylonurus Symondsii, Salter, sp. (P. 124.) 



Upper Beds of the Cornstones, Old Red Sandstone ; Rowlestone, Brecknockshire. 

 Head-shield, nat. size. 



From the Museum of Practical Geology, Jermyn Street. 



5. Stylonurus ensiformis, H. Woodw. Tail-spine, nat. size. (P. 126.) 



Old Red Sandstone ; Turin Hill Quarries, Forfarshire. 



From the Collection of James Powrie, Esq., F.G.S. 



