Researches on the Visual Organs of the Trilobites

The study examines the morphology and function of trilobite visual organs and related structures, with a particular focus on the hypostoma and its maculæ, using comparative description, microscopic sections, and detailed plates. It surveys blind and sighted forms, documents variation in hypostomal outline, grooves, wings, and surface ornamentation, interprets maculæ as internal impressions rather than simple tubercles, and critiques earlier explanations. Systematic descriptions of specimens, methodological notes on preparation, and a literature review support conclusions that synthesize anatomical evidence about sensory structures and attachment features.