British sea-weeds, London, Bell and Daldy, 1872, algae, Great Britain, marine algae, The illustration showcases a series of botanical drawings featuring various species of algae from the genus Spirogyra and Spermothamnion. Each panel highlights distinct structures, detailing their unique characteristics. The top row includes Spirogyra capricus and Spirogyra trilobatis, with elongated filamentous forms displaying intricate spiral chloroplast arrangements. The middle and lower rows present Spirogyra bistora and Spirogyra bromecis, emphasizing typical spiral configurations and cellular structures, while the final panels depict Spirogyra borekiana and Spermothamnion harveyana, illustrating their reproductive features. This collection serves as a visual reference for the diversity and complexity of these