230 The American Geologist. October. 18% 
mined. It is believed that the ice retired with relative (though not ab- 
solute) rapidity in this region, with several pauses, especially at the 
southern rim of the Mohawk basin. The observations do not indicate 
deep and powerful floods in the Chenango valley during the progress of 
the final glacial melting: and an essentially sectional manner of valley 
train deposition is here emphasized. 
24. Origin of ConcjlomerateH. T. C. Hopkins. The source and the 
manner of accumulation of the coarse material in the heavy beds of 
conglomerate in different parts of this country present some difficult 
problems. This is especially true of the conglomerate at the base of 
the Coal Measures; and in few districts is this conglomerate farther re- 
moved from an apparent source than in Indiana. The author showed, 
however, that a considerable portion of this material in Indiana, possi- 
bly all of it, came from the underlying limestone of Lower Carbonifer- 
ous age, being derived from the segregated chert masses, quartz brec- 
cias and geodes contained therein. The evidence in support of the 
statement is, in the main, the finding of geodes and geodic fragments in 
the conglomerate, along with chert fragments. 
25. Origin of Topographic Features in North Carolina. Colliek 
Cobb. 
26. The Cretaceoua Clay Marl Exposure at CUffrvood, N. J. Arthur 
HoLLiCK. This outcrop represents the extreme northeastern extension 
of the formation. It is a bold l)luff, some thirty feet high, more or less 
masked by a talus at the base, and capped by yellow gravel. It is one 
of the few localities where the fauna of the horizon has been collected 
to any notable extent, and is the only one, so far as the author is aware, 
which has ever yielded any of its fossil plants. The material collected 
consists of poorly preserved molluscs, fragments of crustaceans, leaves, 
fruit, and branches of plants, and masses of lignite. 
The crustaceans are too fragmentary for determination. Among 
about fifteen species of molluscs, the following were identified: Pteria. 
petrosa Conr.. Nemoarca cretacea Conr., Cardium ripleyanum Conr.. 
Leiopista protexta (Conr.) Meek, Inoceramus sagensis Owen, Grypha:a 
t7esic?/irtm- (Lam.) Whitf., qx\6. Scalaria hercules Whitf. All of the.se 
had been previously found at or near the same locality. 
About twenty-three species of plants were found, three being provi- 
sionally referred to gymnosperms and eighteen to dicotyledonous angi- 
osperms, while two are of doubtful systematic position. Cunningham- 
ites elegans (Corda) Endl. and Dammara boreal is Heer are the most 
abundantly represented. Species recognized as identical with those of 
the Amboy clays are Laurus pilutonia Heer, Salix protcefolia Lesq., 
My ricafene strata Newb., and Magnolia u-oodbridgensis Hollick. The 
remainder represent either new species or species not before recorded 
from eastern North America. Some are too fragmentary for more than 
generic determination. These specimens are of great interest as repre- 
senting the last phase of Cretaceous land vegetation in this region, the 
next succeeding sediments being purely marine. 
