Transmission electron microscopy has been employed to study the in-plane structure of intercalated Hg guest layers in the stage 1 misfit intercalation compounds alpha-Hg1.19TaS2 and beta-Hg1.3TaS2. Both phases are remarkable for their complex composite crystal structures and for the very different Hg guest layer structures that they exhibit in spite of their similar Hg uptakes, Micro diffraction patterns of alpha-Hg1.19TaS2 suggest a chainlike Hg arrangement. Each Hg atom is surrounded by two nearest neighbor atoms at 2.78 Angstrom and four next nearest neighbors at 3.2 Angstrom. The Hg chains form an ordered sublattice that shares two commensurate axes with the TaS2 host matrix (a and c axes) but is incommensurate along the Hg chain direction (b axis), In the case of beta-Hg1.3TaS2, hexagonal close-packed Hg layers are formed. Here each Hg atom encounters six nearest neighbors at a 2.9 Angstrom distance. The Hg sublattice is rotated by about 30 degrees with respect to the TaS2 host lattice. Thus, the total structure falls close to commensurability : the TaS2 host layers can be viewed as a 2 x 2 superstructure built upon the hexagonal closed packed Hg layers. The Hg arrangements observed in alpha-Hg1.19TaS2 and beta-Hg1.3TaS2 bear a strong resemblance to the (101) lattice planes in solid state beta-Hg and the hexagonal Hg layers in Hg(3)MF(6) (M = Ta, Nb), respectively. This analogy allows us to draw some instructive conclusions about the presence of the Hg metal bonding and its influence on the resulting crystal structures.