Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/167

1869. DAVIDSON—PEBBLE-BED BRACHIOPODA. 77 Lingula Brimonti, Rouault? (according to Salter), Quart. Journ. Geol. Soc. vol. xx. p. 293, pl. xvii. fig. 6.

I believe this shell to have been correctly identified, although no figure was given by the French palaeontologist. Some French examples in the possession of M. de Verneuil, however, are much larger and more transverse than any hitherto collected at Budleigh. I am also of opinion that the shell doubtfully identified by Mr. Salter as L. Brimonti (Rouault) is no more than a malformation of L. Hawkei. It is, according to M. Rouault, a Lower-Silurian species.

4. Lingula? Salteri, Dav. Pl. IV. fig. 5. Sil. Mon. p. 53, pl. i. figs. 27-29, 1866.

I must here repeat what I said when describing this curious species, namely, that whether it belongs to Lingula or Obolus, or to some other genus is a question which the material at my command will not enable me to determine; for none of the specimens showed any portion of their interior. It much resembles Lingula? exilis, Hall (13th Annual Report of the Regents on the state of Cabinet, p. 76, New York, 1860), a shell occurring in the Hamilton group and Marcellus shale of Bridgewater, New York. Prof. Hall's specimens measured about an inch in length, while an example of L. Salteri found by Mr. Vicary had attained 2 inches; it may therefore remain a question whether the American and British specimens do or do not belong to a single species.

Although figured and described in my Silurian Monograph, I cannot say whether it is a Silurian or a Devonian species, as no other known shell has been found with it in the same pebble. I should feel inclined to suppose it Devonian, from its strong resemblance to L. exilis.

Besides the four species of Lingula above recorded, one (Pl. IV. fig. 4) or two specimens, which might perhaps be referable to another type, have been picked up by Mr. Vicary; and of one of these a drawing will be found in pl. i. fig. 31 of my Silurian Monograph.

5. Discina? Vicaryi, Dav. Pl. IV. fig. 6. Sil. Mon. p. 67, pl. vii. fig. 13, 1866.

Three or four examples of this Discina (?) have been obtained by Mr. Vicary; but, as I have never seen the attached valve, I cannot say positively that it belongs to the genus to which it is provisionally referred, nor can I locate it in either the Silurian or Devonian series with any degree of certainty, because no other known species has been found with it in the same pebble.

6. Discina incerta, n. sp.? Pl. IV. fig. 7.

Shell nearly orbicular; apex one-third of the diameter from the margin; upper valve moderately convex. Length 3-1/2, breadth 3, height 1 line.

This shell is apparently rare; and it is not possible to identify it