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1892. | NEW YORK ACADEMY OF SCIENCES. 69 
ciated with elaeolite-syenite. This is true of the localities in the 
Monchique Mountains of Portugal, of the Norwegian exposures, 
of those in Brazil, at Montreal, Magnet Cove, Salem (as recently 
discovered by J. E. Wolff), and Beemerville, and it is possible 
that they may yet be found in the other American localities. The 
dikes lying outside the syenite areas in Arkansas have been re- 
cently described by the writer, and in the paper which has just 
appeared in the annual report of the Arkansas State Survey for 
1890, vol. ii, p. 392, a review is given of those elsewhere. Along 
the eastern side of the Beemerville syenite a number of such out- 
breaks are found. Their determination as porphyrite in the Ameri- 
can Journal of Science for 1888 has since been revised. Although 
the available material is much decomposed, they were shown to 
consist of large biotite phenocrysts with somewhat smaller and less 
abundant auzite, in a groundmass mostly changed to calcite, but 
which was thought to have had close affinities with nepheline. 
Some plagioclase ‘also appeared as a constituent of the groundmass, 
The rocks are dense and black and belong in the Lamprophyre divi- 
sion. In the Arkansas examples much fresher material was af- 
forded, and this, too, from about 75 or 100 dikes. There is almost 
no definite nepheline, but the minerals are in a glass of no great 
abundance. It is probable that this was the original condition of 
these basie dikes at Beemerville. The Arkansas dikes, rich in bio- 
tite (and in instances this forms half the rock), were named ouachi- 
tite, from the Ouachita River, along which they occur. Macro- 
scopically, the ouachitite is indistinguishable from the alnoite of 
Tornebohm (cited from the original Swedish by Rosenbusch, Mass. 
Gest., p. 804), the Norwegian melilite rock, but they contain no 
trace of melilite. 
The New Jersey rocks are mostly ouachitite, with some four- 
chite, and the names are accepted from the later developed locality 
on account of the fresher material. 
There is some underlying genetic connection between the elaeo- 
lite-syenite and these other basic rocks, but what it is I feel at a 
loss to say. Rosenbusch thinks them due toa splitting of his foy- 
aite magma. Other dikes occur at a distance of ten or fifteen miles; 
a number are shown in the map, A. J. 8., Aug. 1889, p. 131. The 
one called mica-diabase hy Emerson, from Franklin Furnace, has 
long been known, and others of the same sort have recently been 
determined by G. HL. Williams for F. L. Nason, in the last annual 
Report of the New Jersey Survey. Rosenbusch, however, says in 
a recent letter to me, regarding some specimens sent him of the 
Franklin Furnace dike, that there is nothing of the true ophitic 
structure of diabase in them, but that they are a lamprophyre of 
unusual type, and near the camptonites. My own observations 
would substantiate this view. 
I have also a curious dike from Hamburg, north of Franklin 
Furnace, that is not yetymentioned in print and that is closely re- 
lated to the theralites. It cuts blue limestone and has some curious 
