OcT., 1907. MeTEORIC StupIES II — FARRINGTON aes) 
compared with the dark-brown to black of the outer zone.* These 
microlites have an elongated form, averaging about .o2 mm. in length 
and tend to a fibrous structure. Succeeding to this inner zone, while 
no structural change is apparent as compared with the interior of the 
meteorite, there is a marked series of cleavage or fracture lines running 
essentially parallel to the crust. These lines, although irregular and 
frequently anastomosing, run at intervals of about .o5 mm. The zone 
showing these lines has a width averaging about .2 mm. 
As regards the remainder of the section, in ordinary light a field of 
silicate and metallic grains is presented, with the siliceous constituents 
exceeding the metallic. There is considerable limonitic staining of 
the silicates and the metallic grains are for the most part bordered by 
a dark zone of the same character. Chondri of spheroidal outline oc- “ 
cur here and there, but are not abundant. They are rather uniform 
in size. Their diameters vary from .5 to 1 mm., being generally about 
.7mm. In structure they present chiefly the familiar ribbed and por- 
phyritic characters produced by combinations of chrysolite and glass. 
The general form of the chondri is spherical but many are plainly frag- 
mental. In outline the chondri are rarely sharply separated from the 
adjoining ground mass, although this is sometimes the case. The 
ground mass of the meteorite exclusive of the chondri is made up of 
crystalline fragments varying from minute grains up to individuals 
.3--4 mm. in diameter. Many of the larger individuals show crystal 
outlines which are more or less rounded. High interference colors 
and strong double refraction show these to be chrysolite for the most 
part. The larger individuals are traversed by cleavage cracks along 
which alteration has frequently taken place. This appears in the form 
of brownish opaque bands which suggest iddingsite traversing the 
fragments. Aside from these the crystals are free from clouding or 
inclusions for the most part. One interesting crystal, however, has an 
- outer transparent portion, while the interior shows glass and skeleton 
growths. The metallic grains consist of nickel-iron and _troilite, 
sometimes singly and sometimes in combination. They have irregu- 
lar branching forms and seem to fill the interstices between the silicate 
erains. Their form shows beyond a doubt that they were subsequent 
in origin to the silicates. 
MEJILLONES. 
Through an error of the writer in copying Wulfing’s classification, 
the specimen of this meteorite in the Museum collection was desig- 
nated * asa brecciated hexahedrite. It is in fact an iron-stone meteor- 
* Pubs. Field Col. Mus. 1903. Geol. ser. Vol. II, p. 107. 
