126 BRITISH FOSSIL CRUSTACEA. 



outer margin. As they are abraded in this unique specimen, their shape and convexity 

 cannot be ascertained ; they appear to have been large and rounded. 



In a communication made by me to the Geological Society in June, 1865, 1 I pointed 

 out that there was now good evidence, from the specimens of other species, discovered, 

 since Mr. Salter described it, by Mr, James Powrie, F.G.S., in Forfarshire, and 

 Mr. Robert Slimon, in Lanarkshire, that the remarkable crustacean carapace, referred 

 by Mr. Salter to Euryjjterus, was a true Stylonurus, agreeing most closely with S. Loyani 

 and S. Poivriei in form. I accordingly referred it to that genus in the paper above 

 quoted, and I see no reason for doubting the correctness of its allocation. 



Formation and Locality. — Old Red Sandstone, Rowlestone, Brecknockshire. No 

 other specimen has since been obtained. 



Species 4.— STYLONURUS ENSIFORMIS :— H. Woodw. PI. XXI, fig. 5. 



Stylonurus ensiformis, H. Woodw. Geol. Mag., 1864, vol. i, p. 198, Woodcut, 



p. 199. 



A tail-spine of Stylonurus, nearly 4 inches long (probably longer when perfect), 

 f ths of an inch in width, and deeply channelled through its entire length, from f-ths at its 

 widest part, and ^th of an inch at its extremity, was found in the Old Red Sandstone 'at 

 one of the Turin Hill quarries in Forfarshire. 



This spine is so peculiar in its form, and so distinct from any other specimen as yet 

 met with, that I have ventured to name it Stylonurus ensiformis. The specimen is in 

 the collection of Mr. James Powrie, F.G.S., of Reswallie. 



Formation and Locality. — Old Red Sandstone, Turin Hill Quarries, Forfarshire. 



Species 5.— STYLONURUS SCOTICUS :— H. Woodw. Pis. XXII and XXIII. 



Stylonurus Scoticus, H. Woodw. Brit. Assoc. Reports, Bath, 1864, p. 73. 



— — 77. Woodw. Quart. Journ. Geol. Soc, 1865, vol. xxi, p. 484, 



pi. xiii, figs. 2 and 3. 



Although not so large as Pteryyotus Anglicus, this species is, perhaps, the most 



1 ' Quart. Journ. Geol. Soc.,' vol. xxi, p. 486. 



