Megascolex, [351], [372], [381], [383]
Megascolides, [349], [358], [372], [382];
body-wall and nephridia, [357]
Mégnin, on parasites, [164]
Meissner, on Polyzoa, [493]
Melania, Coabangia in shell of, [284]
Melanin, [292]
Melicerta, [202], [205], [206], [210], [215], [218], [219], [221], [226];
early description of, [197]