name the various kind of cell layers that constitute the bark.

Bark is formed as a result of secondary growth of cork cambium in the stem of dicots and gymnosperms.

Bark includes all the dead and living tissues outside the vascular cambium. It includes 

(1) Cork (Phellem)

(2) Cork cambium (Phellogen)

(3) Phelloderm

(4) Cortex

(5) Phloem