Book reviews : Schumm,S. A. editor,1977: Drainage basin morphology. Benchmark Papers in Geology 41. Stroudsburg,Pennsylvania: Dowden,Hutchinson and Ross. xi + 352 pp. us $25.00

Dury, G. H. , editor, 1970: Rivers and river terraces. London: Macmillan . (283 pp.)

Mosley, M.P. and Zimpfer, G.L. 1979: Hardware models in geomorphology. Progress in Physical Geography 2, 438-61.

Ruhe, R.V. 1952: Topographic discontinuities of the Des Moines lobe. American Journal of Science 250, 46-56.

Schumm, S.A. and Hadley, R.F. 1957: Arroyos and the semi-arid cycle of erosion. American Journal of Science 255, 161-74.