﻿T. Davidson — On New Scottish Brachiopoda. 13 



the so-called " Kames," owe most of the materials of which they 

 are composed to the ancient glaciers. 



2. — These materials were spread over the bottom of the sea when 

 it was at a higher level than at present, and in the ordinary familiar 

 course of nature. 



3. — The "Kames" owe their present forms not to any abnormal 

 action of the elements, but are the result of the same denuding agen- 

 cies that are at present in operation. 



III. — Notes on Four Species of Scottish Lower Silurian 



Brachiopoda. 



By T. Davidson, F.R.S., F.G.S., etc. 



(PLATE II.) 



Genus Siphonotreta, De Verneuil. 



Of this remarkable genus several species from the Lower Silurian 

 rocks of Eussia have been well described and illustrated by Eichwald, 

 Pander, de Verneuil, Kutorga, and others, to whose works and 

 papers the reader is referred.^ 



In 184:9 Prof. Morris described a species from the Upper Silurian 

 or Wenlock Shale, near Dudley, to which he gave the name of 

 Anglica.'^ In 1851 Prof. M'Coy made us acquainted with a much 

 smaller species, S. micula ^ which abounds in the Llandeilo flags of 

 various English, Scottish, and Irish localities. 



About two years ago Mrs. Gray, an indefatigable collector of 

 Scottish Silurian fossils, to whose liberality I am deeply indebted, 

 discovered in the Caradoc Limestone or Shales of Craighead Quarry, 

 in Aryshire, several incomplete examples of a third species which 

 she kindly placed in my hands for description and illustration. 



It is not, however, possible, from the crushed and fragmentary con- 

 dition in which these specimens have been found, to describe the 

 shell completely, or to refer it, with any degree of certainty, to the 

 Eussian species already noticed. It will consequently be better, 

 I think, to give to this Scottish species a provisional separate 

 designation. 



1. Siphonotreta Scotica, n. sp. ? PI. II. Figs. 5, 6. 



Shell oblong oval, anterior half broadly rounded ; posterior half 

 tapering (in the ventral valve) into an acuminated beak, perforated 

 at its extremity by a small circular foraminal aj)erture. Valves 

 moderately convex and marked with numerous concentric ridges, 

 from which fringes of closely-packed adpressed spines take their 

 rise, which, although more numerous, partake of the character of 

 those figured by Kutorga in pi. vi. fig. 2b. of his Memoir already 



1 Eichwald, Zoologia Specialis, vol. i. p. 274, 1829. Von Buch, Beitrage zur 

 Bestimmung des Gebirgsformation Eusslands, 1840. Kutorga, Ueber die Siphono- 

 treteffi, 1848. De Verneuil, Geol. of Eussia, toI. ii. 1845. Davidson, British Eossil 

 Brachiopoda, vol. i., Introduction, p. 131, 1853, and vol. iii. Sil. Mon. p. 75. 



2 Morris, Annals and Mag. Nat. Hist. vol. iv. No. 23, p. 315, Nov. 1849. 

 s M'Coy, Annals and Mag. Nat. Hist. vol. viii. p. 389, 1851. 



