Complex sentence: The skin consists of a thin outer epidermis, which contains mucous cells and sensory cells, and a connective tissue dermis consisting largely of collagen fibres and various chromatic organs; chromatophores, leucophores, iridophores, reflector cells and photophores.
Split into simpler sentences: The skin consists of a thin outer epidermis overlying a connective tissue dermis. The epidermis contains mucous cells and sensory cells and the dermis consists largely of collagen fibres and various chromatic organs; chromatophores, leucophores, iridophores, reflector cells and photophores.