Using neutron monitor data from 1952 through the end of 1987, including the maximum intensity in early 1987, we have observed several new features which illustrate the importance of a 22-year modulation cycle in addition to the wel-known 11-year cycle. These features include a sharply peaked intensity maximum in 1987, similar to that observed 22 years eartier in 1965, in contrast to the flatter maximum obserbed between 1972 and 1977 and earlier in 1952-1954. We also find that the neutron monitor intensity is ~1.5% higher at the time of the 1987 maximum and also in 1965 as compared to the maximum in 1972--1977 period. Systematic differences in the overall shape of successive 11-year modulation cycles and similarities in the shape of alternate 11-year cycle are observed that seem to be related to the 22-year magnetic cycle, to predictions of drift models, and to the effects of the equatorial current sheet. A very high correlation is observed between the tilt of this current sheet and the neutron monitor intensity over the entire 1984--1987 period. An abrupt increase in the current sheet tilt that occurs in May--June 1987 seems to be directly related to the intensity decreases observed by neutron monitors in the latter part of 1987. ¿ American Geophysical Union 1988