P L A T E _ X I . 



(Sp. Xo. 23675. Natural si:e.) 



This colored plate rejireseuts thi; pnlished surface of au ellipsoid with a portion of the matrix 

 •which surrounds it and separates it from the adjacent ellipsoids. The dense character of the center 

 is nicely shown. Around this oval area we get narrow concentric zones of alternating li_:;ht-grecn 

 and dark-green material. The light-green material corresponds to that in the center, and represents 

 the least-altered basalt of the ellipsoids. The dark-grceii areas are the cUloritized basalt. Beyond 

 this, forming the outermost greeuish-gra.y zoue, one linds the matrix, which possesses distinctly fray- 

 mental characters, though in spite of this with a marked schistose character. The schistosity of the 

 matrix conforms to the contours of the ellipsoid. 

 116 



