white and yellow, and some specimens of a purple colour, veined with dark green, resembling blood stone. 1 ‘ Sienna ’ marble is obtained from several places in King’s County; but the best veined and mottled Sienna is found near Shannon Harbour, on the Galway side. It is susceptible of a high polish, and exhibits bright and distinct colours. 2 In Donegal the bands of limestone are converted into crystalline marble when in proximity to the granite. 3 It is as yet uncertain whether any of this white marble is sufficiently homogeneous and pure for statuary purposes ; but promising specimens have been obtained from Ardes. Scotland. An interesting variety of marble occurs at Tiree, in the Hebrides, where it is associated with Laurentian gneiss. It consists of a base of pink limestone, through which are disseminated crystals of dark green augite, (1) giving the stone a porphyritic appearance. 4 The following are noted by Gwilt. 6 The Iona marble, whose colours are grey and white, sometimes mixed with yellowish spots or 1 Kane, Ind. Res. of Ireland, p. 232. 2 None of these so-called ‘ Sienna marbles ’ are equal in richness to the Italian variety. 3 Report on the Granites of Donegal, by Messrs. Scott, Griffith and Haughton. Brit. Assoc. Rep. 1863. 4 R. Hunt, Descrip. Guide M. P. G. p. 26. The bust of Sir II. T. De la Beche, in the Library of the Museum of Practical Geology, is supported on a block of this marble. 5 Encyc. Arch. p. 494.