The Manchester Content Addressable Image Database is ageneric tool which has been designed for image informatics and computer vision problems. The system stores pre-compuied feature tokens, which are obtained by conventional processing of the input images, into a database which is accessed by a specialised query language (M VQL [1 ]). The M VQL is based on the creation and refinement of groups of features by computing attributes. We illustrate the system with an application concerned with the detection and classification of microfossil images. We use the MVQL to express a projective circular Hough Transform for microfossil detection. We also address the problem of classifying detected structures into six broad morphological groups. This is achieved using MVQL to define "structure" measures from the distribution of curve tokens in a circular region around each microfossil.