active zygote of, [34]

Adambulacral, ossicle, of Asterias rubens, [434];

of Ophiothrix fragilis, [479];

of Asteroidea compared to covering-plates of Crinoidea, [589];

spine, of Asterias rubens, [434]

Adamsia, [377];

A. palliata, [378], [381];

A. rondeletii, [378]

Adaptation to fresh water, [176] f.

Adelea ovata, syngamy of, [101]