70 The American Geologist. ■'"'y- ^^'^'■^■ 
tliis Ingcthcr willi the restrictod occurence here of Gypidula galeatus 
makes its recognition easy. The succeeding stratum, the New Scot- 
land, is a calcareous shale characterized normally by Orthothetes radi- 
ata, Spirifer macropleura and Spirifer perlamcllosa ; but interesting 
transition beds are found between the Coeymans' and New Scotland. 
Upon this rests the Becraft limestone which is composed almost en- 
tirely of crinoid joints. Faunally it is especially characterized by 
Gypidula pseudogleatus and the great abundance of Spirifer concinna. 
The Kingston, the highest member of the old Lower Helderberg group, 
succeeds this. It is rather shaly and in places contains much chert. 
Chsetetes is very abundant in it. Resting upon this is the Oriskany, 
which here is hard limestone, and contains the characteristic Spirifer 
arcnosa and Spirifer arectus, also an abundance of Diaphorostoma 
ventricosa. Upon this rest the Esopus shales which are broken by 
two sets of cleavages into very narrow and thin, slate-pencil-like, 
pieces; while the Schoharie lying upon this cleaves into broad thin 
plates. Upon these shales in one portion of the mountain rests the 
Onondaga limestone. All formations from the Manlius to the Onon- 
daga succeed each other conformably. 
These strata form a .syncline with a gentle dip of io''-i5'' towards 
the centre of the mountain. The structure of tlie northern portion of 
the mountain is very simple, the basin begins with the Manlius on each 
side and the strata follow each other, with perhaps a single fault to 
obscure the perfect succession, to the center of the mountain where 
the Schoharie is found. The southern portion however is much 
more complex. The original simple syncline has been folded and 
faulted to such a degree that they remind us of the Appalachian struc- 
ture. 
While most of the week was employed on Becraft mountain one 
afternoon was also spent in mapping outcrops of Hudson River shales 
on Mt. Merino. On Saturday upon the invitation of Prof. J. C. Smock, 
late State Geologist of New Jersey, the party enjoyed a drive to Mt. 
Bob, a few ,niiles north of Becraft. It is only a half mile long by a 
quarter wide so that a half day was long enough to cross-section and 
map it. The southern portion was found to be a syncline with the 
Manlius forming the basin and only Coeymans resting in it. The 
northern portion had the eastern part of the syncline eroded leaving 
an eastward dipping monocline. 
The significance of the great unconformity at the base of the Man- 
lius was especially impressed upon the students by their work in this 
field. Mluch attention was also paid to the physiography of the region. 
Seventeen students attended the school making a total of twenty. 
Several students from the more advanced classes in geology undertook 
a careful study of the faunas of the Helderberg and Oriskany beds 
devoting all their lime to careful collecting and notation of exact hor- 
izons. The rest of the class was divided into squads of two, and each 
pair made a cross-section of the mountain and mapped a section are- 
allv. Every evening a geological conference was held at which each 
rquad made a report upon their day's work, the conclusions they had 
