G. H. Williams—Norites of the “ Cortlandt Series.” 141 
red inclusions so characteristic of this species, a fact which 
would speak against their having been secondarily formed 
by er ienanone which Professor Judd states is attended 
by a bleaching of the original mineral substance. The ex- 
tinction of the mineral is in all sections parallel to the crys- 
tallographic axes. In sections parallel to the basal- or macro- 
pinacoids, the bisectrix may be seen to stand perpendicular 
to the face and the optical angle to be smaller in the latter case 
than in the former. This fact, taken in connection with the 
deep colors exhibited by the mineral, ‘s sufficient to place its 
nature as true hypersthene beyond a doubt. 
The only other constituents observed in this rock are biotite, 
irregularly dispersed in small quantities, and a considerable 
amount of apatite and magnetite or ilmenite. 
All the feldspar of this norite, both orthoclase and andesine, 
is filled with inclusions of such great beauty and delicacy that 
they seem to merit a description, 3. 
especially on account of their bearing 
upon the former remarks of the writer 
regarding Professor Judd’s theory of 
Schillerization.* These inclusions, 
which are represented in fig. 3 as 
magnified about 350 diameters, con- & 
sists of plates, rods and minute dots. 
1. The plates.—The color of these 
is either red, grading as they become 
thinner into shades of orange and 
yellow; or greenish-gray. They are 3 
sometimes hexagonal, sometimes rectangular and sometimes 
irregular in shape. Almost always they are finely serrated for 
a portion of their edge. The largest measure about 0:04 x001 
mm. From this size they grade down to the minutest dots, 
always, however, transparent, homogeneous and very sharply 
outlined. These plates do not exercise any influence upon 
polarized light. This is, however, on account of their extreme 
thinness as ‘compared with the mineral in which they are im- 
bedded. These plates very strongly resemble extremely thin 
crystals of hematite (micaceous iron, eisenglimmer) and the 
writer is inclined to regard them as composed of this substance. 
2. Fods.—When very minute, the above described plates are 
frequently arranged in parallel rows, which grade insensibly, 
into long, hair-] like rods. These are sometimes discontinuous, 
a mere series of dots, through a part or the whole of their 
length; sometimes they are thickened in certain places. Often 
these rods may be seen to be continuous with the plates, and, like 
them, they are always transparent with a brown color except 
* This Journal, January, 1886, p. 33. 
