As far as the design of the book is concerned, we chose to be selectively limited, in sense of pulling the diverse information on mammalian species, for the just reason of avoiding overburden of matter and yet have deliberately tried to cover vast datum populace for each of the mammal so chosen. Further for maintaining the structural clarity, we have re-divided each chapter in systemic manner covering all the major systems of living organism. We are earnestly sure that this categorical approach will be of help not only to the researchers and students of the subject of comparative anatomy but also to those with whom we share the same audacious spirit of curiosity.