218 E. 8. Dana—Stibnite from Japan. 
has a length of 7 inches, the planes are mostly sharp and dis- 
tinct; another crystal, remarkable for its symmetry, but much 
rounded on the edges, for the opportunity to examine which 
the writer is indebted to Mr. Clarence S. Bement of Philadel- 
phia, had a length of 74 inches and a thickness of 14 (macro- 
diagonal) and 2 inches (brachydiagonal). 
The bending over of the crystals in the direction of the 
macrodiagonal axis is a very common peculiarity of these crys- 
tals, and seems to be characteristic of the species. This has 
been described at length by Krenner, who mentions crystals so 
bent as to form a complete ring. With the Japanese crystals this 
bending is generally confined to the termination, but in some 
cases it has gone. so far that the edge is bent between two adja- 
cent pyramidal planes (p ort) so as to make a right angle with 
itself. Sometimes this results in a simple rounding over of the 
pyramidal planes, but more commonly they are separated into 
series of successive apparent planes. This irregularity is so 
common that it is not easy to find crystals, even among the 
smaller individuals, which are quite free from it. Thus in a 
specimen consisting of a group of small crystals almost all are 
found to be more or less curved at the extremities. Fortunately 
means, and, though this is not generally true, in all cases it ap- 
pears as if produced subsequent to the formation of the crystal. 
More rarely the slender prismatic crystals have a cork-screw-like 
wist. 
crystals are often terminated by a striated surface, having the 
position of the basal plane, but doubtless to be regarded only a8 
a “gleitflache.” oaks | 
exact determination of the axial ratio for the Japanese 
* Jahrb. Min., 1883, ii, 19. 
