Recently, M. W. Ovenden has raised seemingly plausible dynamical arguments which suggest that a 90-earth-mass planet existed in the present location of the asteroid belt until 16×106 years ago, and then rapidly disintegrated. He mentions supporting evidence from the cosmic ray exposure ages of chondritic meteorites. If the long-period comets originated from the recent disintegration of such a planet, several otherwise improbable characteristics of their orbits would be predicted, including a tendency for those orbits which are least perturbed to return to the site of the original break-up. In this investigation, we compare observed characteristics of long-period comet orbits with expected characteristics, based on the missing planet hypothesis. The conclusion is that long-period comet orbits are wholly consistent with the hypothesis; indeed, certain of their characteristics are difficult to explain in any other way.