LINGULA. 307 



Lingula Scotica, Davidson. PI. XLVIII, figs. 27, 28. 



LlNGl LA SCOTICA, l)av. Moii. of Scottish Carb. Bracli., pi. v, ligs. Mi, 37, 1860. 



Spec. Char. Shell of an elongated triangular shape, tapering at the beak, slightly 

 rounded laterally and in front. The valves are slightly convex, but much compressed, 

 while the entire surface is covered with numerous minute, concentric striae, with still wider, 

 flattened interspaces. Interior unknown. Dimensions variable ; two examples have 

 measured — 



Length 15, width 12^ lines. 



05s. This remarkable species, which has at times exceeded the proportions above given, 

 is easily distinguished by its triangular shape, tapering sides and beaks, as well as by the 

 delicate and peculiar sculpture which adorns its surface. In shape it approaches to certain 

 exceptional examples of Phillips's Lingula cuncata, but the Carboniferous and Silurian 

 species cannot be confounded. 1 



L. Scotica has not been hitherto discovered either in England or in Ireland. In 

 Scotland it occurs at Gare, in Lanarkshire, at 239 fathoms below the " Ell Coal," and 

 from which locality it has been known to a friend in Carluke for upwards of thirty years. 

 My attention was, however, first directed to the shell by Mr. Young, of the Hunterian 

 Museum, Glasgow, who had been struck by its peculiar triangular appearance, and it was 

 subsequently discovered at Robroyston, north of Glasgow, in beds upon a similar horizon 

 to those of Gare, while the larger examples were procured by Dr. Slimon from Hall Hill, 

 Auchenhcath, and Coalburn, Lesmahago, about 300 fathoms below " Ell Coal." 



Lingula mytiloides, Sowerby. PL XLVIII, figs. 29 — 36. 



LlNGULA jivtiloides, Sow. Min. Con., tab. xix, figs. 1, 2, 181C. 



— elliptica, Phillips. Geol. of York., pi. xi, fig. 15, 1836. 

 margin ata, Phillips. lb., fig. 16, 1836. 



— parailela, Phillips. lb., figs. 17— 19, 1836. 



— mytiloides and L. parallela, Portlock. Report on the Geol. of London- 



derry, &c., pi. xxxii, figs. 6—9, 1843. 

 — De Koninck. Desc. des Anirn. Foss. de Belgique, pi. vi, fi<>\ 9, 



1843. 



— — l)av. Mon. of Scottish Carb. Brachiopoda, pi. v, fi?s. 38 



43, 1860. 



1 I possess also an American Lingula from the Pottsdam Sandstone of the Falls of St. Croix, 

 Minnesota, which is stated by Mr. Worthen to be the oldest American species of the genus. In shape it is. 

 very similar to L. Scotica, but differs from it in sculpture, as well as in the convexity of its valves. 



