1. Hodge, V. F., Hoffman, F. L. & Folsom, T. R. Health Phys. 27, 29 (1974).
2. Wong, K. M., Hodge, V. F. & Folsom, T. R. Nature 237, 460 (1972).
3. ZoBell, C. E. Nova Hedwigia 32, 269 (1971).
4. Dobson, T. in Marine Insects (ed. Cheng, L.) 447 (North-Holland, Amsterdam, 1976).
5. Oldroyd, H. Discovery 15, 198 (1954).