1888.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 167 



the process of trituration the sharp poiuts of the couical fragments 

 would be readily broken away and the fragments thus assume the shape 

 shown in the figures. 

 National .Museum, June 18, 1888. 



Explanation of Plate xxxv.— Showing Microstructure of the San Emigdio 



Meteorite. 



(The outlines as here shown were drawn with the aid of a camera lucida.) 



Fig. 1.— Portion of slide 47333-5 magnified fifty diameters. The perfectly black 

 areas are metallic iron: the large, colorless, angular area, with slight radiate struct- 

 ure is eustatite : all the clear portions are olivine. The finely dotted portions repre- 

 sent simply portions so finely pulverulent and stained by iron oxide as to render un- 

 safe any attempt to represent it by a pen drawing. 



Fig. 2.— Portion of slide 47833-3 magnified fifty diameters. The black areas are 

 metallic iron; the large radiating angular fragment in the lower center enstatite. 

 All the other clear, partially shaded or finely granular portions are olivine. The 

 rounded form at the right of the enstatite fragment is a monosomatic chondrus; the 

 one just above. polysomatic. The somewhat rounded, elongated, triangular form just 

 above the upper left corner of the enstatite is pyrrhotite. The finely dotted portions 

 as in Fig. 1. 



Figs. 3, 4, and 5.— Fragments of olivines in slide 47833^2. In Fig. 5 the finely dotted 

 portion repiesents an amorphous dark gray, nearly black, glass, from which has been 

 secreted the olivines shown by the colorless areas. Particles vary from 0.2 to 0.3o mm 

 in greatest diameter. 



Fig. 6.— Fragment of enstatite in slide 47333-1. Actual size, 0.37™ m . 



Fig. 7.— Fragment of polysomatic chondrus. consisting of clear, colorless olivines 

 in a partially devitrified base, section 47833-3. Actual size, 0.85 mm . 



Fig. 8.— Finely granular and porphyritic fragments in section 47S33-1. Actual size 

 of largest fragment, 0.60 mm . 



Fig. 9.— Barred and granular form in section 47833-3. All that portion with the 

 parallel-lying horizontal bars belongs to one crystal. The rounded granular areas at 

 the extreme right are crystallographically independent. The whole forms one frag- 

 ment. Actual size, 0.59 mm . 



Fig. 10.— Irregular mass of native iron. The rounded embayments are occupied by 

 olivines and enstatites. Actual size, 0.55 mm . 



