The solar neighborhood.: XVIII.: Discovery of new proper-motion stars with 0.4" yr-1 > μ ≥ 0.18" yr-1 between declinations -90° and 47°

We report 1606 new proper-motion systems in the southern sky ( declinations -90 degrees to -47 degrees) with 0.40" yr(-1) > mu >= 0.18" yr(-1). This effort is a continuation of the SuperCOSMOS-RECONS ( SCR) proper-motion search to lower proper motions than reported in Papers VIII, X, XII, and XV in this series. Distance estimates are presented for the new systems, assuming that all stars are on the main sequence. We find that 31 systems are within 25 pc, including two systems ( SCR 0838-5855 and SCR 1826-6542) that we anticipate to be within 10 pc. These new discoveries constitute a more than 10-fold increase in new systems found in the same region of sky searched for systems with mu >= 0.40" yr(-1), suggesting a happy hunting ground for new nearby slower proper-motion systems in the region just north ( declinations -47 degrees to 0 degrees), much of which has not been rigorously searched during previous efforts.