found at Makariwa, near Liver car gill, New Zealand. 61 



order, varying between light yellow and bluish-grey, and extinction 

 takes place in an undulating manner, mostly parallel to tlie fibration. 

 In reflected light it looks yellowish and opaque. The remainder of the 

 section consists of olivine, in part finely granulated, in part in larger 

 and smaller grains, sprinkled with particles of nickel-iron and dark 

 grains of iron ore. At the left-hand margin, nearly enclosing two 

 particles of nickel-iron, is a large grain of olivine which is divided 



Fi&. 2. 



into colnmnar portions by rudely parallel fractures in the line of 

 which extinction takes place between crossed nicols. In the finely 

 granalated centre of the figure, scattered larger grains of olivine 

 produce quite a porphyritic appearance which becomes more pro- 

 nounced through the different optical orientation and the fine polar- 

 isation-colours of these larger grains. The largest particle of nickel- 

 iron encloses a grain of olivine in the centre ; and a deep indentation 

 of another particle of the metal, seen close above the enstatite 

 chondrule, is occupied by an olivine grain showing an optic axis (oa) 

 in convergent polarised light. Some particles of the nickel-iron have 

 narrow, dark margins, produced, no doubt, by oxidation. 



Fig. 3. — Xear the centre of the figure is represented a fine granular 

 chondrule of olivine surrounded by a rim of clear grains of this 

 mineral, the divisional joints of Avhich stand generally radial. The 

 optical orientation of this rim and that of the centre part are different, 

 the latter uniformly extinguishing between crossed nicols when the 

 rims of the grains are bright, while all the grains become dark simul- 

 taneously when the centre part is bright. Below this chondrule, near 

 the lower right-hand margin, is a rather rudely-radial arrangement of 

 olivine grains around a centre part consisting of four grains of this 

 mineral, but in this case the centre grains extinguish simultaneously 

 with the surrounding ones, thus proving the whole to be a large 



