stage of Lobata and Cestoidea, [414]
Mertensiidae, [417]
Mesenchyme, [604]
Mesenteric filaments, Alcyonaria, [331], [333];
Zoantharia, [369]
Mesenteries, of Alcyonaria, [329], [334];
of Zoantharia, [329], [366] f., [368];
of Asterias rubens, [439];
of Holothuria nigra, [562];