Macrogonidia of Volvox, [126], [127]
Macro-, prefix misused to mean "large," usually replaced here by "mega," q.v.
Madrepora, [368], [373], [387], [389], [395];
M. forma cervicornis, [395];
M. forma palmata, [395];
M. forma prolifera, [395]
Madreporaria, [369], [371], [384] f.
Madrepores, [326] = Madreporaria, q.v.
Madreporic vesicle (or right hydrocoel) of Asterias rubens, [448];
of Ophiothrix fragilis, [490];