Final answer:
Oozoids of doliolids are barrel-shaped organisms with a gelatinous structure and various internal organs for locomotion, reproduction, and digestion.
Step-by-step explanation:
The structure of oozoids of doliolids varies depending on the specific species, but generally, oozoids are barrel-shaped organisms composed of a gelatinous substance. They have an outer cuticle that protects the internal organs and sensory structures. Inside the oozoid, there is a muscular system used for locomotion, as well as reproductive and digestive organs.