Concurring Opinion by
Mr. Justice Cohen :I concur in the opinion of Justice Eagen but feel compelled to comment on Justice Roberts’ observation that “appellees’ express admission of jurisdiction which caused appellants to continue their suit in the wrong forum thus preventing a timely action in the proper court” constitutes an equitable estoppel. I .cannot find an “express admission” in a failure to contest *143jurisdiction, but, even if I could, the question whether “the matter in controversy exceeds the sum or value of $10,000” is not readily discernible and one’s acquiescence or resistance to federal jurisdiction should not generate an estoppel. See, Snyder v. Harris, 394 U.S. 332, 37 L.W. 4262 (1969).