or membranous test

2. With gelatinous 4
or membranous test

3. a. Attached forms:

1. Without a stalk, or with Genus *_Monosiga_
a very short one

2. With a long, simple, stalk Genus *_Codonosiga_

3. With a long, branched, stalk Genus _Codonocladium_

b. Free-swimming Genus _Desmarella_

4. Colonial, and with a gelatinous Genus _Proterospongia_
covering

* Presence at Woods Hole indicated by asterisk.


KEY TO FAMILIES AND MARINE GENERA OF HETEROMASTIGIDA.

1. Two flagella nearly equal in size Family _Bodonidæ_

One main and 2 accessory flagella Family _Trimastigidæ_

Family _Bodonidæ_: