Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, Plates / Report on the Scientific Results of the Voyage of H.M.S. Challenger During the Years 1873-76, Vol. XVIII

A plate volume presenting hundreds of detailed illustrations and taxonomic descriptions of Radiolaria, organized by major groups (Spumellaria, Nassellaria, Phaeodaria, Acantharia). Each plate pairs magnified drawings with notes on morphology, shell and spicule architecture, internal anatomy, colony forms, measurements, and diagnostic characters, plus a map of geographic distribution. The work functions as a systematic visual reference for identification and classification, documenting species diversity, morphological variation, and microscopic structure observed in specimens collected during a nineteenth-century oceanographic survey.