THE following notes deal with the gemmule development of Espevc/(afibmxiZis (n. sp.) and Tedania Bvtlcei (n. sp.), to which are added a few observations on the egg development of Teda-?zio?ie f i f i d a (n.g.) and Hircinia acufa. EspidZa fib?-cx. is a small silicious sponge abundant near Wood's Holl, Mass. T h e others are Ihhama forms found at Green Turtle Cay, the two silicious sponges, Tedania and Tedanione being closely related.
During the summer, Esperella and Tedania contain great numbers of good-sized embryos in all stages of development, and if the sponges are kept in aquaria for a few hours, some of thc embryos will pass out through the oscula. T h e embryos thus set free are solid oval bodies covered with cilia, and are quite like the egg larvze of many silicious sponges. They swim about for a day or so and then attach themselves to the wall of the dish, flatten out and undergo a metamorphosis. When the embryos inside the mother are examined, they are found not to be egg embryos, but true gemmules, i.e.