  By adopting the approximations suggested in the theory of thin shells, the
hydrodynamic theory of liquid crystals established by Eriksen [Arch. Rational
Mech. Anal. 4 (1960) 231; Trans. Soc. Rheol. 4 (1960) 29] and Leslie [Adv. Liq.
Cryst. 4 (1979) 1] is modified so that it is applicable to study the lipid
bilayer membranes.
