228 ON A LOWER-CARBONIFEROUS CRUSTACEAN. 



well with fig. 1 ; and although nearly the whole of the black- 

 ened crust has disappeared, still the casts of the seven spines 

 preserved exhibit their form and length in a marked degree ; and, 

 what is more, we have in this specimen a view of the bluntly 

 rounded ends of these spines ; for fortunately they terminate on the 

 immediate edge of the matrix, or, perhaps, rather, the latter has been 

 fractured there. The other specimen is the largest fragment of 

 all, but has only three spines preserved, two of which, the outer 

 ones, are of very considerable size ; the elongated spine-like squama? 

 between them are also well marked and larger than those in any of 

 the other specimens. It is not improbable that both these speci- 

 mens, with Nos. 1 and 2, may even be the posterior portion of the 

 dorsal surface of the carapace itself, rather than that of one of the 

 somites, a suggestion which is borne out by the size attained by 

 one of Mr. Powrie's specimens. 



5. Locality and Horizon. — Preston Quarry, near Dunse, on a 

 similar horizon to the last. 



Discussion. 



Mr. H. "Woodward remarked that the remains of Eurypteri 

 from the Carboniferous rocks are so distinct from the Upper-Silu- 

 rian Eurypteri of America, Shropshire, Lanarkshire, and Russia, 

 as probably to entitle them to be placed in a distinct genus ; and, 

 indeed, at some future day, when more remains are obtained, they 

 may perhaps have to be arranged among the Arachnida, along with 

 many curious fragments which have been called Arthropleura, dis- 

 covered by Mr. M'Murtrie in the Radstock Coal-field, by Mr. Jordan 

 in the Saarbriick Coal-basin, and by Mr. Gibbs in the Manchester 

 Coal-field. Eurypterus Scouleri occurs at Kirton with Sphenopteris 

 Bibberti in a remarkable siliceous deposit, probably thrown down 

 by an old thermal spring in the Carboniferous period. 



Prof. Ramsay remarked that the rock from which the fossils were 

 derived seemed to him to be pretty nearly the equivalent of the 

 Burdie-House Limestone, which he had long ago thought might be 

 to a considerable extent formed by calcareous deposits from thermal 

 waters, probably during a period of great volcanic activity. This 

 would be in favour of Mr. Woodward's opinion. 



