Mr. Wallace exhibited photographic figures of Coleoptera: plates of Lucani, of the natural size, were conspicuously successful; other insects of smaller size, but magnified twice in linear dimensions, were not so successful. Mr. Wallace called attention to the mode of mounting these smaller species on pieces of gelatine instead of cardboard: this rendered the use of gum unnecessary, since all that was requisite to fix the insect was to moisten the under side; moreover, the gelatine was so transparent that the under side of the insect was available for examination.