118 THE CRYSTAL FALLS IROX-BEARIXG DISTRICT. 



till' uiiit'di-m c'luiracter of the zones in the fragments, the original material 

 was \-ery homogeneous, most probably a basalt glass. 



The spaces between the fragments are occupied by a finely crystalline 

 aggregate of quartz and chlorite, with a small amount of epidote. This aggre- 

 gate outlining the original fragments owes its origin most probably to the 

 process of infiltration. The long axes of the quartz grains and chlorite flakes 

 in this aggregate usually show a general parallel arrangement. Moreover, the 

 long directions of the fragments are in general parallel with each other, and 

 with the quartz-chlorite aggregate between them. This parallelism results in 

 giving an imperfect schistosity to the matrix. The schistosity of the matrix 

 is in general parallel to the contours of the ellipsoids which it surrounds. 



Origin of the ellipsoidal structure. — Ellipsoidal stTucturcs similar to those just 

 considered have been described by various authors.^ 



' On coliininiir, fissile, and spheroidal structure, by T. G. Bonney: Quart. Jour. Geol. See, Vol. 

 XXXII, 1876, pp. 140-1."34. 



Ueber niechanische Gesteinsnmwandlungen bei Hainichen in Sacbsen, by A. Rotbpletz : Zeitscbr. 

 dent. (ieol. Gesell., Vol. XXXI, 1879, pp. 374-397; Vol. XXXII, 1880, p. 447. 



Report on tbe geology of northern New Brnnswick, by R. W. Ells: Ann. Rept. Geol. and Nat. 

 Hist. Survey of Canada, 1879-80, D, p. 24. 



E. Datbe: Jarb. K. prenss. geol. Landesanstalt, 1883, p. 432. 



K. Calmer: Cf. Zirkel Pet., Vol. II, p. 650. 



Report on the geology of the Lake of the Woods region, by A. C. Lawson : Geol. and Nat. Hist. 

 Snrvey of Canada, 1885, CC, pp. 51-.53. 



The greenstone-schist areas of the Menominee and Marquette regions, by G. H. Williams: Bull. 

 U. S. Geol. Survey, No. 62, 1890, pp. 137, 166-168, 175, and 203. 



On the variolitio rocks of Mont Genevre, by G. A. J. Cole and J. W. Gregory : Quart. .Jour. Geol. 

 Soc., Vol. XLVI, 1890, pp. 29.5-332. 



On a variolitio diabase of the Fichtelgebirge, by ,T. W. Gregory: Quart. .lour. Geol. Soc, Vol. 

 XLVII, 1891, pp. 45-62. 



Tbe Kawishiwin agglomerate at Ely, Minnesota, by N. H. Wiuchell: Am. Geol., Vol. IX, 1892, 

 pp. 359-368. 



The eruptive rooks of Point Bonita, California, by F. L. Ransome: Bull. Dept. of Geol. Univ. 

 of Cal., Vol. I, 1893, pp. 71-114. 



Editorial note on the above paper, by N. H. Winchell: Am. Geol., Vol. XIV, 1894, p. 321. 



The geology of Angel Island, by F. L. Ransome: Bull. Dept. Geol. Univ. of Cal., No. 7, 1894, 

 p. 202. 



Variolite of the Lleyn and associated volcanic rocks, by C. Raisin: Quart. .Jour. Geol. Soc, Vol. 

 XLIX, 1893, pp. 145-165. 



On a radiolarian chert from Mnllion Island, by H. Fox and J. J. H. Teall: Quart. ,Jour. Geol. 

 Soc, Vol. XLIX, 1893, p. 211. 



On greenstone associated with radiolarian chert, by .1. J. H. Teall: Trans. Roy. Geol. Soc. of 

 Cornwall, 1894: Cf. Rosenbusch, Mikroskopische Physiographie, 3d ed., p. 1064. 



The volcanic rocks of the Michigarame district, by J. M. Clements: .Jour. Geol., Vol. Ill, 1895, 

 p. 808. 



The geology of Point Sal, liy H. W. Fairbanks: Bull. Uept. Geol. Univ. of Cal., Vol. II, 1896, 

 p. 40. 



Geology of the Fox Islands, Maine, by G. O. Smith, 1896, pp. 16-18. 



The Ancient Volcanoes of Great Britain, by Sir Archibald Geikie, London and New York, 1897, 

 pp. 26, 184, and 193. 



