This book is designed for wide range readers such as for a layman it will be helpful as a pictorial guide, a popular science book for the students, text book for the undergraduate and postgraduate students, research documentation for the researchers and a valuable document for the scientists. Since, there is a large scale of morphological diversities exists between the different families of bivalves and gastropods and proper identification of all these species becomes a menace for the researchers, students and even to a common man. Therefore, this book will help to fill the missing link. This book is the reality of a dream viewed by a child while moving in a beach and now as an author begs to the almighty that it may get a splendid success. Since similar kind of publications are scarce in the contemporary literature based on identification and distribution of mollusca, certainly this book will be the milestone towards the molluscan research.