protocneme
/ˈprəʊtəkniːm/ /ˈprəʊtɒkniːm/ /prəʊˈtɒkniːm/Zoology. Now rare
noun
In zoantharian coelenterates, especially sea anemones and stony corals: any of the primary mesenteries, which are usually arranged in six pairs.
Origin
Early 20th century. From proto- + ancient Greek κνήμη tibia.