Spallanzani, on Oligochaeta, [348]

Sparganophilus, [366], [386];

anatomy, [355].

Spatangus, as host, [298]

Spencer, on Land-Planarians, [34];

on earthworms, [349], [380]

Spengel, on Gephyrea, [440]

Spermatheca, of Dinophilus, [243];

of Oligochaeta, [362], [363], [364]

Spermatophores, [27], [402]