A8 BRITISH SILURIAN BRACHIOPODA. 
M‘Coy describes or mentions a Lingula under the above name from Doonquin, Dingle, 
County Kerry, and a figure of it will be found in our plate. It is certainly a distinct 
species. —J. W. S. | 
? Lineuta minima, J. de C. Sow. Pl. II, figs. 36—44. 
Lincuta minima, Sow. Silurian System, p. 612, pl. v, fig. 23, 1839. 
_ —  unguiculus, Salter MS. 
Spec. Char. Shell small, oblong, elongated ; sides curved, gradually merging into the 
slopes forming the acuminate pointed beaks; front rounded; valves slightly convex and 
marked with fine concentric striz. Two specimens measured— 
Length 4, width 23 lines (Sowerby’s type). 
5 1b) sy, 024 . SetG@allesmaharo specimen): 
Obs. The reason for retaining this form as a separate species, or a named variety of 
LI. cornea, has already been stated. Mr. Salter has given the MS. name of LZ. wnguiculus 
to some small Lingulz (in the Museum of the Geological Survey, figs. 42—44 of our 
Pl. If) which occur, with a spiral shell, in beds at the top of the Ludlow rocks at Birken- 
head Burn, near Lesmahago; but these so closely resemble some of the Downton sand- 
stone specimens of L. minima, that we prefer, at least for the present, placing them with 
the latter. Prof. Phillips, at p. 276 of vol. ii, part 1, of the ‘Memoirs of the Geological 
Survey,’ states that he found Lingula minima, Sow., in the Downton sandstone of Brock 
Hill, in the Malvern district. 
Downton sandstone. Sir R. Murchison, Prof. Ramsay, and Mr. Salter examined the sections in his 
company; and all agreed in considering them to be higher in position. 
Mr. Lightbody kindly sends me the following note with reference to his locality :—“In the ‘ Downton 
sandstone,’ which underlies the ‘ Passage-beds,’ I have never found any Mollusca except L. minima and a 
species of Modiolopsis. The ‘Trochus-bed’ is at the bottom of the Downton sandstone; and about three 
or four feet lower is the ‘ Bone-bed,’ which is nearly at the top of the mudstone. Spirifer elevatus occurs 
in a layer a little under the ‘Bone-bed;’ and, lower still, Pterinea retrofleca. These upper beds are 
yellowish, and underlie the first quarry of Whitcliff next Ludford, and are thin and very fossiliferous— 
Chonetes lata, Rhynchonella navicula, Rh. nucula, Orthis lunata, O. elegantula, Goniophora cymbeformis, 
Serpulites longissimus ; and most of these fossils occur also in the Lower Ludlow below; but in true 
Upper Ludlow I have never seen Atrypa reticularis, nor any Strophomene. These last come in with the 
Aymestry upper beds abundantly; but these beds have been sometimes, and especially in Whiteliff, 
confounded with the Upper Ludlow, and consequently the RA. navicula band has been put too high up. 
This bed really belongs to the Upper Aymestry limestone ; and even above it can still be seen traces of the 
honeycomb-structure which has been referred to by Sir R. Murchison as characteristic of the Aymestry 
limestone. These Upper Aymestry beds are interlaced with calcareous bands, which the Upper Ludlow is 
not; and below them the limestone gets stronger, and composes the mass of the rock, though still too 
argillaceous to burn into lime. Below this again come the beds of Pentamerus Knightii, like an oyster-bed 
crammed full of shells crushed together; this they burn as lime. Then come the Lower Ludlow beds ; 
and, as seen at Mocktree, one cannot tell where the Aymestry limestone ends and the Ludlow begins in 
that fine section along the turnpike-road.”” 
