Soften gelatin in water, and set aside.
Combine tomato juice and next 6 ingredients in a large saucepan; bring to a boil. Reduce heat, and simmer 10 minutes. Strain tomato juice mixture; add gelatin, stirring until dissolved. Pour into 4 lightly oiled 1/2-cup molds; chill until mixture is firm.
Unmold on a lettuce-lined serving plate. Garnish with a dollop of mayonnaise; sprinkle with paprika.