Plate P1. Magnification for specimens is 2000x. Light micrography: PH = phase-contrast light, PL = plain transmitted light, XP = cross-polarized light. 21-24. Fasciculithus tympaniformis, Sample 173-1068A-10R-3, 123-125 cm, PH (21), PL (22), and XP (23, 24).