On Pourtalesia; a Genus of Echinoidea, by Sven Ludvig. With Twenty One Plates.Sven Ludvig Lovén1883ZIP
Practice of Fish Diseases : with Twenty-one Plates and One Hundred and Seventy-three FiguresMarianne. Plehn1941ZIP
Sir Edwin Landseer, R.A., by James A. Manson; Illustrated with Twenty-one Plates, and a Photogravure Frontispeice.James Manson1902ZIP
Contributions to the Life Histories of Gordius Robustus (Leidy) and Paragordius Varius (Leidy) with Twenty-one Plates, by Henry Gustav May.Henry May1920ZIP
School Atlas of Astronomy; Comprising, in Twenty-one Plates, a Complete Series of Illustrations of the Heavenly Bodies. New and Enl. Ed., with an Elementary Survey of the Heavens, Designed as an Accompaniment to This Atlas by Robert Grant.Alexander Keith Johnston1877ZIP
