Slide showing six diagrams of 'gills of various Terebellids.' Slide shows six black and white diagrams of 'gills of various Terebellids.' (Terebellidae is a family of polychaete worms). The diagrams are labelled 'A' to 'F' Diagram 'F' has further labelling 'm', 'g' and 't' which are explained in the key. Title below images reads: 'Fig. 176 - Gills of various Terebellids. x4. A, Amphitrite johnstoni Mgrn; B, Terebella nebulosa Mont.; C. T, conchilega Pall,; D Nicolea Mgrn.(the finer branches are not indicated); E. Pista Mgrn.; F, Terebellides Sars (after Malmgren), g, Gill; m, mouth; t, tentacles.' Late 19th to early 20th century