114 Brush and Dana—Fairfield County Minerals. 
1842, records the occurrence of “ bitumen” in connection with 
the trap rock of Connecticut. Those who are fortunate enough 
to possess a copy of this report will find that Percival with his 
usual accuracy of observation, mentions several times the occur- 
rence of this substance while ‘describing the Triassic formation 
of the Connecticut Valley. Mr. Per cival speaks aera of 
“indurated bitumen” as occurring in the cavities of a i 
trap, and in small veins in the indurated shale ausinieie Asso- 
ciated with these rocks occur, also, bituminous limestones and 
shales piaaiiins fossil fishes Similar bituminous rocks he 
describes as occurring in the small isolated Triassic area of 
Southbury and Woodbury in Western Connecticut. In refer- 
ence to the reported discovery of coal in Connecticut the state- 
ment is made* that ‘This substance, however, is a more or less 
indurated bitumen, similar to that occasionally occupying the 
pores of amygdaloid, or sh metallic veins in the trap 
and tbe adjoining indurat sandstones, and is perhaps derived 
from the same volcanic source as the trap it accompanies 
It will be noticed from the above that the bitumen described 
by Percival has the same geological associations as the mineral 
occurring at Plainfield, N. J. A specimen of this mineral from 
Connecticut which we have just cig eigee from Dr. H. C. Bolton 
of Trinity College, and obtained by him from seams in tra] 
which this mineral is associated in Connecticut correspond in 
lithological characters and geological position with the eruptive 
rock of New Jersey, and are a portion of the great system of 
trap ridges which traverse the Triassic formation in Connecticut 
and Massachusetts 
enema 
Arr. XII—On a new and remarkable mineral locality in Fairfield 
County, Connecticut ; with a description of several new species 
occurring there; by Geo. J. Brust and Epwarp §. Dana. 
First Paper. 
[Continued from page 46.] 
3. DickINsonITE. 
Physical characters.—Dickinsonite occurs most commonly in 
crystalline masses, which have a distinctly foliated, almost mica- 
ceous, structure. It is also lamellar-radiated and sometimes 
stellated, the laminze beh usually more or less curved. This 
massive variety forms the gangue in which crystals of eosphorite 
are often imbedded, and also sometimes triploidite. It more- 
* Percival’s Geol. Rep. of Conn., p. 452. 
