F. The River-Bed.

The portion of the bed of the Rangitata River in the area under examination, some 12 km. long, is characteristic of the larger rivers crossing the Canterbury Plain, with its swift, anastomosing streams, and its wide stretches of large boulders margined by flood plains, and backed by steep terraces some 30 m. high. The successions from bare river-bed by way of an open community of Raouliae and Epilobiae to Discaria toumatou shrubland, Coprosma shrubland, or low tussock-grassland, are the same in essentials as those described in the papers of Cockayne (1911), Cockayne and Foweraker (1916, p. 175), and