Bula Soup

1 (10 ounce) package frozen spinach,
    cooked and well drained
8 ounces clam juice
8 ounces minced clams with juice
8 ounces chicken stock
1 1/2 cups half-and-half
2 tablespoons fresh lemon juice
1 tablespoon Worcestershire sauce
Pepper, to taste
Chilled sour cream

In a blender or food processor pur