38 BRITISH SILURIAN BRACHIOPODA. 
lineation of its surface, which is invisible to the naked eye, but under the lens 
presents a beautifully reticulated sculpture. As many as about twenty-six of these raised 
striae may be counted in the breadth of one line towards the middle of the shell. It is 
not always, however, that we find specimens having their outer surface preserved, most 
examples being decorticated and of a black colour. I have seen a great many specimens 
of this shell sometimes showing both valves united; but in no case did the beak of the 
ventral valve so much exceed in length that of the dorsal one as is described and repre- 
sented by. Prof. M‘Coy,—“ the beak of the larger valve extended a quarter of an inch 
beyond the ventral margin of the other.” 
In size and shape the shell under description so closely agrees with Lingula Canadensis, 
Billings (‘ Geology of Canada ; Palaeozoic Fossils,’ vol. i, p. 114, fig. 95, June, 1862), that 
I am almost tempted to place this last as a synonym of LZ. tenuigranulata ; but not having 
seen specimens of the Canadian shell, and as Mr. Billings states that it is less wide and 
more coarsely reticulated, it will for the present be better to leave the question undecided. 
In size, L. tenuigranulata much exceeds LZ. Lewisii, L. granulata, and L. quadrata of 
Eichwald, &c. 
Position and Locality. This species appears to be at present known only from the 
Caradoc (?) beds. It is common in the sandy and calcareous schists of Alt-yr-Anker, 
Meifod, and in sandy Bala schists of Das Eithin ridge, Hirnant, Montgomeryshire ; 
from whence the specimens described by Prof. M‘Coy were obtained. I have seen 
numerous examples from the Bala shales north of Llanfyllin, Fron-goch, Meifod, near 
Welshpool ; Pwill-y-wrach, near Llanwddyn, and Pistyll Cwmllech, Llanfyllin, &. Prof. 
Harkness has also found small specimens of this species in the Lower Bala shales (“ Dufton 
fossiliferous shales” of Harkness) at Pusgill, near Dufton, in Westmoreland. Mr. Edgell 
has it also from the Caradoc of Cheney Longville, Salop. 
Lineura ovata, A‘Coy. PI. I, figs. 19 —23. 
Lingua ovata, M‘Coy. Synopsis Sil. Foss., Ireland, p. 24, t. iii, fig. 1, 1846. 
Spec. Char. Flongated, greatest width about the middle; sides sub-parallel, nearly 
straight or very slightly convex, and merging gradually, so as to form an acuminated 
pointed beak ; front very little rounded, sometimes almost straight; valves depressed, 
their convexity being very small; the surface is almost smooth, or marked with fine 
concentric lines of growth. Professor M‘Coy’s figured specimen measured 
Length 15, width 8 lines. 
Oés. This common species is distinguished from LZ. Lewisii by its greater length 
in proportion to its width; and (as remarked by Prof. M‘Coy) it bears much resemblance 
in shape to some specimens of the well-known Carboniferous Z. sguamiformis. Its 
