The Four O'Clock Spoon runs in length from 4 3/4 to 5 3/8. It is shorter in length than the Five O'Clock spoon at 5 to 5 5/8 inches and much shorter than the place teaspoon, usually 5 7/8 to slightly over 6 inches. It is longer than the Demitasse spoon which is usually 3 3/4 inches to 4 1/2 inches. You may be able to tell a Demitasse from a Five O'Clock spoon, but without seeing all four laid out together, it could be confusing. I imagine many people are using Four O'clock spoons thinking they are place teaspoons. Oh, and to confuse matters there is the Desert spoon, but since it ranges from 6 7/8 to 8 inches, chances are it will not get confused in the mix.
Maryland by Gorham ( 4 7/8 inches)
Rosette by Gorham (5 inches)
Saint James by Tiffany (4 5/8 inches)
Charles II by Dominick and Haff (5 1/4 inches)
Lotus by Gorham (4 3/4 inches)