Table I lists determinations of radial velocity from 281 spectrograms for 114, mostly southern, long period variables. The wavelength and velocity systems are investigated for both absorption and emission lines. Relative velocity shifts between different emission lines are discussed. A new mean relation of absorption minus emission line velocities to period is derived (Fig. 1) using more than twice the previously available material. This relation is used to obtain absorption velocities for many variables for which only emission velocities have been measured. Table II gives a homogeneous set of velocities for 405 long period variables arranged in nine groups according to period and other characteristics. A detailed study of S Ind in the 1953 cycle shows relatively rapid velocity changes soon after maximum light. Other observed phenomena are related to these changes. The results on S Ind are compared with those for other stars (Section 6). Spectral types and luminosity classes are given for the Me variables (Sections 7 and 8 and Table I). A considerable spread in luminosity is indicated, especially at the shorter periods (Fig. 3). The mean results agree fairly well with the statistical parallaxes. Peculiarities in the ratio Cr I 4254/ Fe I 4250 are noted for some stars in agreement with previous findings for the variables in 47 Tuc. 353 Me variables are divided into seven groups (Table II) according to period, corrected for basic solar motion, and analysed for residual systematic motion (Table IV). There is no K -term or deviation of the antapex from the direction of galactic rotation. The results (Fig. 12 and Section 11) show that the Me variables cover almost the whole range of population types. The anomalous motion of the stars with periods less than 149 days suggests that these stars are variables pulsating in the first overtone. The ratio of the pulsation constants Q0 / Q1 is estimated as about 2.4 (Section 12), larger than for RR Lyrae stars and in agreement with the larger value of Q0 (0.056) also derived (Section 14). Comparison with the Woolley-Eggen classes of stars leads to ages and masses for the longer period stars similar to those of the Hyades giants. The shorter period stars have ages and masses similar to RR Lyrae stars of period about 0 d .45 and stars in metal-rich globular clusters. The bulk of the Me variables are associated with Disk and Intermediate Population II. is derived, considerably smaller than that appropriate to extreme Population I objects but in agreement with the prediction from the velocity ellipsoids and systematic motions for the Me variables of mean period near 250 days. Differential galactic rotation for the Se variables leads to M υ = −3.4, in agreement with the determination of Takayanagi but brighter than the results recently obtained from statistical parallaxes.