A. Aschelminthes |
1. Body
segmentation like rings |
B. Mollusca |
2. Often worm shaped, elongated
|
C. Annelida |
3. Exoskeleton
of cuticle, jointed appendages |
D. Arthropoda |
4. Worm-like
with proboscis, collar and trunk |
E. Hemichordata |
5. External skeleton of shell usually present |
|
6. Notochord,
dorsal hollow nerve cord |