Suitable polymerizable ethylenically unsaturated monomers containing one or more mesogenic or rodlike moieties per molecule are represented by the Formulas XXXVI or XXXVII: ##STR16## wherein n and R1 are as hereinbefore defined, M is a group containing two or more aromatic rings bridged by a rigid central linkage, R3 is a divalent hydrocarbon group having from one to about 12 carbon atoms and may