THE PETROGRAPHICAL PROVINCE OF ESSEX COUNTY 803 
aegirite. The pyroxenes are represented by a very pale, green- 
ish-gray aegirite-augite (C /\ c= 34°) and by green aegirite. The 
former occurs in quantity only in one specimen from Salem 
Neck with biotite. The egirite is abundant in many sections, 
often in those free from biotite. It is clear grass-green, with 
strong pleochroism: g—deep grass-green, b — grass-green, 
¢ light greenish-yellow. The extinction ¢ /c is about Vinge 
Titanite, magnetite, and zircon are rare; apatite occurs in 
patches, but is not common. No eudialyte was seen. A few 
grains of a yellow, strongly pleochroic mineral, referred to 
laavenite, were found. 
I II III 
SiO, - - - 58.77 59.31 60.39 
TiO, - - - 0.31 0.32 
ZrO, - - >= Ou Lee ce 
Al,O3 - - 22.64 22.50 22.51 
Fe,03 - - Sela 4 1.93 0.42 
FeO - - - 1.04 1.40 2.26 
MnO - - - trace trace 0.08 
MgO - - : 0.19 Only, 0.13 
CaO - - - 0.74 0.46 0.32 
BaO - - - none reas sieges 
Na,O - - - 9.62 7-98 8.44 
K,O - - - 4.89 4.08 ey Ay 
H,O(110°—) - - 0.07 0.15 Site 
H,O(110°-+)-  - 0.90 Tele 0.57 
100.82 99-42 99-95 
I Nepheline-Syenite. Salem Neck. H.S. Washington anal. 
II Nepheline-Syenite. Great Haste Island. H.S. Washington anal. 
III Litchfieldite. Litchfield, Maine. L. G. Eakins anal. BayLey, Bull. Geol. 
Soc. Amer., Vol. III, p. 241, 1892, contains trace of CO,. 
The foyaites show their structure in the hand specimen very 
clearly, most surfaces exhibiting a multitude of long, glistening 
cleavage surfaces of feldspar, arranged in parallel position, form- 
ing a sort of flow structure. Surfaces in one direction, however, 
are made up of flat isometric feldspar plates, owing to the tabu- 
lar development of the crystals parallel to 6 (o10). They are 
clear ash-gray, and not very fine grained. In thin section they 
