FEB., 1906. THE SHELBURNE METEORITE. 11 
together in the manner indicated in Plates IX and X is a somewhat 
conchoidal one, indicating a scaling off from a larger mass. Such 
a form, as is well known, is exhibited by other meteorites, notably 
that of Butsura among stones and Cafion Diablo among iron mete- 
orites. Such a form would be especially liable to fracture during 
descent. Borgstrém remarks that the larger stone is characterized 
by concave surfaces. This is also true of the smaller one, and of 
Butsura as well. The two parts when placed together in the manner 
indicated in Plates IX and X correspond perfectly as regards front 
and rear sides. The rear side of each is concave, smooth, and has 
broad, shallow pits. The front side is concave, rough, and has small, 
deep pits. 
The pittings of the two surfaces of the smaller stone shown in 
Plates V and VII differ in character from those of the other surfaces. 
These surfaces may be said to be rougher than the others in the 
sense that the roughness is due to a greater abundance and smaller 
size of the pittings. The shape of the pittings is irregular, but in 
general, saucer-like with diameters of .5°to 1 centimeter. On the 
face shown in Plate VII the pittings tend to become elongated in 
character, with the long axes parallel with the long direction of 
the surface. The edges which both these rough surfaces make 
where they join the other surfaces of the meteorite are much sharper 
than the edges of other parts of the meteorite. These sharper edges 
and roughness indicate less exposure to fusion and erosion, and 
therefore a mid-atmospheric fracture along these surfaces. The 
largest pits on the meteorite are on the surfaces shown in Plate 
VIII. One depression here shows an area of about 3x3:cm. anda 
depth of tr cm. Secondary pits break the configuration of this, but 
all have sloping, rounded edges, showing fusion and erosion during 
the entire aérial passage of the meteorite. The depressions on the 
‘rear side, that shown in Plate VI, are still broader: and shallower in 
character and blend in with the general surface so as to nearly lose 
the character of pits. 
The crust of the meteorite is uniformly black in color. While 
in general smooth in appearance, it is seen even with the naked eye 
to be dotted over with minute grains rising above the general surface. 
These are for the most part protruding metallic grains whose bright 
surface can be discovered by filing. Besides these the crust may 
be seen under a lens to be abundantly stippled with clots and threads 
which anastomose and blend with one another, producing hollows 
and elevations. The threads rarely extend more than a few milli- 
