Shells of the World: A Natural History

M G Harasewych
Princeton University Press, £25.00

Shells are more present in our lives than we may realise – from having practical uses, such as a source of food, to being of ornamental value, or educational value, given their origins, evolution and geological history. Harasewych’s book focuses on marine molluscs, invertebrates with diverse geological and biological histories that are distributed worldwide.

The introduction includes details of shell composition and formation, characteristics that are greatly influenced by the surrounding environment (water chemistry, pH, and temperature for example). The shells provide an archive of the environments in which the molluscs lived, and evolutionary trends and relationships are explored.

The bulk of this book is devoted to six of the eight classes which comprise the phylum Mollusca on the basis that the remaining two are shell-less. Covering a range of topics, from the Polyplacophora (chitans), thought to be the closest relative of the two shell-less classes, to the Bivalvia, which comprises 50,000 living species and can weigh up to 225 kg, through to the Scaphopoda, considered to be the youngest class of Mollusca which have been used as currency and clothing decorations by Pacific Northwest Native Americans for centuries, it also looks at Cephalopopda, the most highly evolved and intelligent group. 

This book, which has a glossary as well as further reading recommendations, will be of interest to specialists and non-specialists alike, with well-organised informative content and abundant colourful and striking illustrations.

Dr A M Mannion

Reviewed by Dr A M Mannion, Honorary Fellow at the University of Reading Department of Geography