3 to 5. Protozoa. : 5. Blastaeades. Multicellular hollow spheres. : 5. Catallacta. Magosphaera, Volvocina, Blastula.
STAGES 6 TO 11. INVERTEBRATE METAZOA ANCESTORS.
6 to 8. Coelenteria, without anus and body-cavity. : 6. Gastraeades. With two germ-layers. : 6. Gastrula. Hydra, Olynthus, Gastremaria.
6 to 8. Coelenteria, without anus and body-cavity. : 7. Platodes I. Platodaria (without nephridia). : 7. Cryptocoela. Convoluta, Proporus.
6 to 8. Coelenteria, without anus and body-cavity. : 8. Platodes II. Platodinia (with nephridia). : 8. Rhabdocoela. Vortex, Monotus.
9 to 11. Vermalia, with anus and body-cavity. : 9. Provermalia. (Primitive Worms.) Rotatoria. : 9. Gastrotricha. Trochozoa, Trochophora.
9 to 11. Vermalia, with anus and body-cavity. : 10. Frontonia. (Rhynchelminthes.) Snout-worms. : 10. Enteropneusta. Balanoglossus, Cephalodiscus.
9 to 11. Vermalia, with anus and body-cavity. : 11. Prochordonia. Chorda-worms. : 11. Copelata. Appendicaria. Chordula-larvae.
STAGES 12 TO 15. MONORHINA ANCESTORS.
Oldest vertebrates without jaws or pairs of limbs, single nose. : 12.
Acrania I. (Prospondylia.) : 12. Amphioxus larva.