Pātuhitia tēnei: The calibration of photographic and spectroscopic films : the utilization of the digital image processor in the determination of aging of the surf clam (Spisula solidissima) : semi-annual report, May 1, 1987 - October 30, 1987 / by Kevin A. Peters and Ernest C. Hammond, Jr. ; submitted to NASA, Laboratory for Astronomy and Solar Physics, Goddard Space Flight Center.