LINGULIDAS, 43 
Spec. Char. Shell depressed, slightly convex; very much elongated; sides 
usually more or less sub-parallel for about half their length from the front, and from 
thence gradually sloping by gentle curves until they unite at the beaks; front very gently 
curved, almost truncated. Surface marked with numerous concentric lines of growth, 
which at intervals are more strongly indented, and by very fine radiating striee, which in- 
tersect the concentric ones. Interior unknown ; but two depressions or pits in the cast are 
seen close to the extremity ofthe beak. Proportions variable ; two specimens measured— 
Length 13, width 8 lines. 
eines 7, 
Obs. Some thirty or more examples of this curious shell have been found by Mr. 
Vicary in the pebbles of grey and reddish sandstone or quartzite at Budleigh Salterton, in 
Devonshire, and were at once identified by Mr. Salter as agreeing with the descriptions 
published by M. Rouault in 1850. Mr. Vicary found specimens of all stages of growth, from 
three lines in length to nearly two inches. It would not be quite correct to say that the sides 
are always strictly parallel for more than half the length of the shell ; for in many examples 
they begin to gradually taper almost from the front, as may be seen in the specimens 
figured. In France Lingula Lesueurt occurs at Guichen, in Brittany, in a white or bluish 
sandstone or quartzite, belonging to the Lower Silurian series, and forming part of M. 
Rouault’s “étage du gris Armorican.”’ In Great Britain we do not find this sandstone 
in sité; but these and other fossils of the “Armorican stage” occur in well-rolled 
pebbles or boulders, which vary from a small size to that of a man’s head, and which 
are generally of a flattened oval form.” ‘These boulders, together with others con- 
taining fossils apparently of another period, appear to have been drifted from some dis- 
tance, and to have been accumulated in a bed, whose greatest thickness is stated by Mr. 
Vicary to be a little over a hundred feet. In his paper “On the Drifts in parts of War- 
wickshire,” published in the British Association Reports for 1865, and also in the ‘ Geo- 
logical Magazine,’ vol. 11, p. 566, 1865, the Rev. P. B. Brodie mentions having found 
L. Lesueuri, together with Orthis redux, in quartzose pebbles and sandstone, similar to 
those described by Mr. Vicary from Budleigh Salterton. 
It may still remain a question whether the shell which in the Museum of the Geological 
Survey bears the manuscript designation of Lingula Bechet, from the Upper Llandovery 
of Marloes Bay, may not be a variety of Z. Lesueurz, for some of the specimens quite agree 
in shape with the Budleigh Salterton examples, though the surface is far rougher. 
M. Rouault observes that his species approaches most nearly to Z. Muensterit, D’Orb., but 
that it may. be distinguished from it by its more regular form, and the complete absence 
of three longitudinal furrows which characterise the Bolivian shell. 
1 See Messrs. Vicary and Salter’s paper on the “Pebble-bed and Fossils of Budleigh Salterton,” 
‘Quarterly Journal of the Geol. Soc.,’ vol. xx, p. 283, 1863. 
2 Mr. Salter has lately published (‘ Geol. Mag.’ April, 1866,) his view that these sandstones and shales 
of Brittany are of the age of the Arenig or Skiddaw slates (the “‘ Lower Llandeilo” of Murchison). 
