THE PETROGRAPHICAL PROVINCE OF ESSEX COUNTY 807 
umptekites occurring at Curtis’ Point, Beverly, and other locali- 
ties of the Massachusetts region, and also refers the nepheline- 
syenite of Red Hill, N. H., to this type.* The umptekites, 
however, are typically soda-hornblende rocks, and markedly 
higher in lime and magnesia, as seen in analysis IV Dhevecer- 
tainly show greater analogies with the pulaskites as defined by 
Brogger: ‘ Nepheline-poor to nepheline-free rocks, also quartz- 
free or very poor in quartz, poor in dark minerals and with 
eugranitic structure, in which a development of the feldspars 
with rectangular or long rectangular sections predominates.” It 
is of interest to observe also the affinity with the albite-rich 
litchfieldite. A rough calculation of the analysis II gives albite 
about 58.5 per cent., orthoclose about 31.5, anorthite about 2, 
and the rest (8 per cent.) colored minerals and magnetite. This 
rock, then, may be called a pulaskite, or rather a pulaskitic phase 
of the nepheline-syenite. It must be borne in mind, however, 
that both this and the hedrumite are only facies of the main 
foyaitic mass, and not independent rock bodies, at least so far as 
is yet known. 
Orbicular syenite.—A small but interesting type of syenites 
is found near Bass Rock, Gloucester, and also, according to Mr. 
Sears, at Salem Neck, Beverly, and on the Manchester Shore, 
the development being in all cases quite local. Near Bass Rock, 
the only locality examined by me, it occurs as rounded inclos- 
ures in an outcrop of granite, apparently in place, together with 
similar masses of a dark, coarse-grained dioritic rock, which will 
be described later. A narrow compound dike of aplite cuts the 
granite and its inclosures. Of the occurrence of Mr. Sears’ 
specimens I have no data at hand. The syenites are fine- 
grained and compact, with a groundmass of a light-gray color. 
Scattered through this are phenocrysts of black hornblende some 
0.5 c.m. long, each hornblende being surrounded by a narrow 
zone of white, finely granular feldspar. ‘These small areas of 
black with white borders give a peculiar orbicular appearance to 
the specimen. 
Cf, RosENBUSCH, Elemente d. Gesteinslehre. 1898, pp. 113. 
