348 T. W E. DAVID, F. B. GUTHKIE, AND W. G. WOOLNOUGH. 



In Scotland a nepheline-bearing rock, described as a trachytoid 

 phonolite, occurs at Traprain Law in the Garlton Hills. 1 This 

 phonolite, which occurs in the form of a neck is remarkable for its 

 high geological antiquity, being of Carboniferous Age. Borolanite 

 (a rock formed of soda-orthoclase, a little plagioclase, melanite, 

 biotite, a little pyroxene, nepheline as elseolite, apatite and a very 

 little magnetite, with probably sodalite), occurs as intrusive dykes 

 or sheets in older Palseozoic rocks near Lake Borolan, Elphin and 

 Achiltibuie in Scotland. 2 



In France a number of interesting phonolite 'necks,' (over 100 

 in number) have been described in the neighbourhood of Velay, 

 Cantal and Mount Dore, Central France. Nepheline is present 

 only in some varieties, its place being taken mostly by nosean and 

 hauyne. In some cases the felspars consist of kernels of anortho- 

 clase, coated with sanidine. 



In Saxony phonolites of the trachytoid type have been described 

 from Obersdorf near Zittau, while numerous nephelinoid phonolites 

 have been described from various parts of Bohemia, such as 

 Teplitz, Schlossberg, etc., 4 as well as from the Rhon region. 



1 " It is essentially formed of a mass of little sanidine prisms, in which 

 lie*ragged crystals of bright green soda-augite. There are also present 

 colourless patches which contain little crystals of nepheline with zeolitic 

 decomposition products." 



2 Trans. R. Soc, Edinburgh, xxxvn., Nr. 11, 1892. 



3 Von Lasaulx, Phonolith vom Mont DoreN. Jahrb.f. Min. 1872, p. 351. 

 Michel Levy, Phonolithes des Mont Dore, Bull. Soc. Geol. (3) xvin., 1890, 

 795 - 821. Michel Levy, Phonolithes vom Cantal, Comptes Rendus xcviu. 

 1884, Nr. 22. Fouque et Levy, Phonolithes des Cantal, Mineralog. Micro- 

 graphique, 1879. Termier, Phonolithes des Velay, Comptes Eendus ex., 

 ] 820, 730. 



4 The literature is too extensive to quote in detail. The following may 

 be^mentioned :— M6hl, Nova Acta Leop. Carol. Acad, xxxvi., Nr. 4, 1873, 

 and^N. Jahrb. f. Min. 1874, 38. Boricky, Sitzgsbr. bohtn. Ges. Wissensch. 

 19, April 1891, and Petrog. Stud, an den Ph.-Gesteinen Bohmens Archiv. 



.d. Naturwiss. Landesdurchforschung von Bohmen in. Bd., 2 Abth. 1 

 Prag. 1874. G. vom Rath, Phonolith voa Zittau, Z. Geol Ges vm., 1856, 

 291. Sandberger, N. Jahrb. f. Min. 1888, ii., 248; and Exc. N. Jahrb f. 

 Min. 1881, ii , 211. F. Zirkel., Mikr. Bescb. 394, 396, and Z. Geol. Ges. 

 xi., 1859, 534. G. vom Rath, Correspondenz-Blatt natuih. Vereins, 1866, 

 46® K. Vogelsang, Z. Geol. Ges. xlii., 1890, 47, etc. For the above 

 references as well as for many others in this paper, the authors are 

 indebted to the great work of Ferdinand von Zirkel, " Mikroscopische 

 Beschaffenheit der Mineralien und Gesteine." 



