NCreateSessionWithTokenOrName - Ever seen this?

I have a WebSphere servlet which extracts the LtpaToken cookie from the request and creates a Domino session with:

session = NotesFactory.createSession(null, sessionToken);

It fails with the following stack trace:

java.lang.UnsatisfiedLinkError:

lotus/domino/local/Session.NCreateSessionWithTokenOrName(String;String;String;)

at lotus.domino.local.Session.createSessionWithTokenOrName

at lotus.domino.NotesFactory.createSessionC

at lotus.domino.NotesFactory.createSession

at com.servlets.axolotl.DominoAccess.getResults

at com.servlets.axolotl.DominoAccess.doPost

Anyone ever seen NCreateSessionWithTokenOrName? I haven’t found any documentation, nor the library it may be hiding in.