Green and Seiberg showed that, in simple treatments of fermionic string
theory, it is necessary to introduce contact interactions when vertex operators
collide. Otherwise, certain superconformal Ward identities would be violated.
In this note, we show how these contact terms arise naturally when proper
account is taken of the superconformal geometry involved when punctures
collide. More precisely, we show that there is no contact term at all! Rather,
corrections arise to the ``na\"\i ve" formula when the boundary of moduli space
is described correctly.Comment: 14pp., 2 figures (included