Clathrulina, [71], [73], [74]

Clava, [272];

C. squamata, [263]

Clavatella, [267], [270]

Clavatellidae, [270]

Clavidae, [272]

Clavularia, [330], [334], [344];

C. viridis, [329], [337], [343] f., [344]

Clavulariidae, [344]

Clearing of tissues, physical explanation of, [11]