CLASSIFICATION OF IGNEOUS ROCKS 163 



(2127) Beloeilite. O'Neill^ described a ''feldspathic tawite" 

 from Mount St. Hilaire (Beloeil), Quebec, intermediate in composi- 

 tion between sodalite-syenite and tawite. This rock may be called 

 beloeilite and may serve as the type of the sodalite rocks of the 

 family. 



(2129) A soda-sussexite of Hackman^ and a nephelite-sodalite- 

 syenite of O'Neill^ belong here. 



(2130) Toryhillite. Adams and Barlow'' described a nephelite- 

 rich albite rock from Toryhill, Monmouth Township, Ontario- 

 The rock falls near the center point of this family; therefore a new 

 name is here suggested. 



(2 131) Urtite Ramsay. Urtite is a feldspar-free nephelite 

 rock, described by Ramsay.^ The name is derived from the second 

 part of Lujavr-Urt, where the rock was first found. It consists of 

 82 to 86 per cent nephelite, 12 to 18 per cent aegirite-augite, and 

 2 per cent apatite. IjoHte Ramsay and Berghell,^ with 51.6 per 

 cent nephelite, and monmouthite Adams and Barlow,'' with 

 77.6 per cent feldspathoid (of which 72 is nephelite), also belong 

 here. The leucite rock of this family is fergusite Pirsson.^ Only a 

 single occurrence is known. It consists of 65 per cent pseudoleucite 

 and 35 per cent mafites, chiefly diopside. The mehlite rock of 

 the family is represented by uncompahgrite Larsen.' It is a 



'J. J. O'Neill, "St. Hilaire (Beloeil) and Rougemont Mountains, Quebec," Geol. 

 Surv. Canada, Mem. 43 (Ottawa, 1914), p. 46. 



^V. Hackman, "Neue Mitteilungen iiber das Ijolithmassiv in Kuusamo," Bull. 

 d. I. Comm. Geol. d. Finlande, No. 11 (Helsingfors, 1899), p. 24. 



3 J. J. O'Neill, op. cit., p. 41. 



4 Frank D. Adams and Alfred E. Barlow, "Geology of the Haliburton and Ban- 

 croft Areas, Province of Ontario," Geol. Surv. Canada, Mem. 6 (1910), p. 273. 



sWilhebn Ramsay, "Urtit,ein basisches Endglied der Augit-syenit-Nephelinsyenit- 

 Serie," Geol. Foren. i. Stockh. Forkandl., XVIII (1896), 463. 



6 Wilhelm Ramsay and Hugo Berghell, "Das Gestein vom liwaara in Finland," 

 Geol. Foren. i. Stockk. Forkandl., XIII (1891), 304; also V. Hackman, op. cit., supra, 

 p. 20. 



' Frank D. Adams and Alfred E. Barlow, op. cit., p. 277. 



8 Louis Valentine Pirsson, "Petrography and Geology of the Igneous Rocks of the 

 Highwood Mountains, Montana," U.S. Geol. Surv., Bull. 237 (1905), p. 88. 



'Esper S. Larsen, "Melilite and Other Minerals from Gunnison County, Colo- 

 rado," Jour. Wash. Acad. Sci., IV (1914), 473. 



