—— on abrupt range of shells in depth, [175].
—— on poorness of palæontological collections, [288].
—— on continuous succession of genera, [316].
—— on continental extensions, [357].
—— on distribution during glacial period, [366].
—— on parallelism in time and space, [409].
Forests, changes in, in America, [74].
Formation, Devonian, [334].
Formations, thickness of, in Britain, [284].
——, intermittent, [290].