U

1. Ulva, 286, 290

2. Undertow, 537

3. Units, fundamental, 400

4. Upwelling:

   1. effect on annual variation of tempcrature, 131, 132

   2. effect on content of plant nutrient in surface layer, 246, 247

   3. importance to organic matter in sediments, 1044

   4. off coast of California, 724, 725

   5. off coast of Peru, 702, 703

   6. off Somali coast, 696

   7. off west coast of North Africa, 671

   8. off west coast of South Africa, 627, 628

   9. process, 140, 501

5. Urnormal-1937, 51