536 THE JOURNAL OF GEOLOGY. 
sandy, and it soon passes into the wave-built terrace to be seen 
in the lower part of the Chatham cemetery. The clearly defined 
cliff above the bowlder-strewn cut terrace, and the graduation 
of the latter into the distinct wave-built terrace, make this one 
of the best marked features of the extra-morainic basin. 
Along the southeastern or front face of Long Hill, narrow 
terraces with steep rock slopes above may be observed in several 
places. Probably not all of them, and perhaps none of them, 
are to be ascribed wholly to the lake. Some of them may be 
benches and cliffs of differential degradation, due to the con- 
trast in hardness between the trap and the underlying Triassic 
sandstone, which here and there have their junction at or near 
the lake level. This, however, will not account for all of 
them. Northwest of New Providence there is a distinctly 
marked bench in the sandstone, at an elevation of 367 to 369 
feet. It can be traced almost continuously into a well-marked 
spit a mile west of New Providence. Because of this connec- 
tion, especially, its reference to the lake seems proper. 
Near the outlet at Moggy Hollow, a mile and a half west by 
north of Liberty Corner, there are slight traces of wave cutting. 
The phenomena are such as would be produced on a gently 
sloping, rocky shore against which the waves had beaten but a 
short time, and where the finest material had been carried away, 
leaving the ill-rounded pebbles where they originated. Both 
above and below the zone thus affected, the rock is covered by 
a much deeper layer of residuary soil. The height of the mean 
lake level at this point, as shown by other evidence, was between 
351 and 356 feet. 
After everything possible has been said in favor of the lacus- 
trine origin of the terraces and cliffs found around the lake 
basin, it must be admitted that, were the proof of the existence 
of the lake dependent upon them alone, its existence could not 
be stoutly maintained. There is not a terrace in the extra- 
morainic part of the basin, the wave-cut character of which, 
taken by itself, can be said to be beyond question. 
B. Constructional forms. 1. On the trap, shale and gneiss 
