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We present preliminary results of the analysis of x-ray pulse-height spectra of very late dwarf M stars as obtained with the ROSAT PSPC. The majority of the data are derived from a program of pointed observations. The limited sample is comprised of both active dMe stars and quiescent dM stars. The basic cornal properties are derived and compared among the dMe and dM stars in the sample. We find that two-temperature fits are required to account for the x-ray emission of dMe stars while single-temperature fits appear to adequately represent the x-ray properties of the non-dMe objects. In addition, we estimate emission measures and coronal loop parameters. The implications for coronal structure will be discussed. In particular, we suggest on the basis of these preliminary results that the coronae of low mass dwarfs are highly geometrically extended relative to the stellar radius. This may account for both the high absolute values of L$_x~$ and the high relative values, i.e., L$_x~$/L$_{bol}~$, that characterize the x-ray emission levels of the dMe stars as compared to that of more nearly solar-type stars.
