W. Campbell Smith — Borolanite from Roaa-Hhire. 153 



In a later paper ' Dr. Teall points out tlie similarity between the 

 rocks of Cuoc-na-Sroine and those of Christiania. He again mentions 

 the dyke-rock as being allied in mode of occurrence and mineral 

 composition to the tinguaites of Eosenbusch, but differing from these 

 in containing 5 per cent, of lime, and also in structure. Accordinglj-, 

 after much hesitation, he has classed it as borolanite. He also 

 discusses the relations between the rocks of Cnoc-na-Sroine and 

 those of Magnet Cove, Arkansas, and regards borolanite as almost 

 identical with the leucite-syenite of the latter locality. To support 

 this theory he compares the analyses of the dyke-rock with that of 

 the leucite-syenite. The quotation of this analysis in this place seems 

 to have led to its being accepted by llosenbusch as that of " Borolanit 

 vom See Borolan ". The same analysis has also been taken as that of 

 "Borolanite, Borolan, Scotland" by Washington and by Osann in 

 their collections of analyses. 



In a paper,* " Ueber Borolanit und die Gesteine des Cnoc-na- 

 Sroine Massivs in I^ord- Schottland," Dr. J. Shand points out the 

 above-mentioned error. In the part of this paper which deals with 

 borolanite the author distinguishes between the typical rock (as 

 originally defined) and the spotted variety. He has paid most careful 

 attention to the micrographic intergrowth with orthoclase, and to the 

 nature of the zeolite. He considers that the former consists of sodalite 

 or analcime, and applies to the finger-print structure, which it forms 

 with the orthoclase, the term 'dactylotype '. The exact nature of 

 the zeolite is still rather uncertain, and, pending further results, he 

 retains Brogger's term ' Spreustein'. 



Hoping to throw light on the ' psendo-leueite ' theory raised by 

 Professor Derby, Dr. Shand analyzed some of the white patches cut 

 from a specimen from AUt a' Mhuilin ; he also analyzed some of the 

 black material. The figures obtained were as follows : — 



I. Black material without visible pseudo-leucite. 

 II. Pseudo-leucite. 

 III. Pseudo-leucite of Serra de Tinga, Brazil. 

 Analysis III is quoted for the sake of comparison. 



1 Geol. Mag., 1900, Dec. IV, Vol. VII, p. 386. 



2 NeuesJahrb.f. Min., etc., 1906, Beilage Baud xxii, p. 413. 



