1. PHYLUM CHORDATA THREE COMMON CHARACTERISTICS
I. NOTOCHORD; a cartilage support
rod sometime during development.
II. DORSAL NERVE CORD ;central nerve or ‘spinal’ cord along the back.
III. PHARYNGEAL GILL SLITS; Pharynx=throat region, some time during development (embryo)

3. SUBPHYLUM UROCHORDATA
CLASS ASCIDIA; Sea squirts
sessile filter feeders on dock floats and dock pilings.
CLASS THALIACEA; Tunicates
colonial, sessile and pelagic filter feeders
Salps, pelagic, transparent barrel shaped filter feeders.

6. SUBPHYLUM CEPHALOCHORDATA
LANCELETS; Amphioxus, small fish like ancestors of vertebrates.
Filter feeders living in sandy bottoms.

7. SUBPHYLUM VERTEBRATA THE VERTEBRATES
VERTEBRAL COLUMN of bone or cartilage.
SKULL enclosing brain etc.

8. CLASS AGNATHA The Jawless Fishes
LAMPREYS; salt and freshwater parasites on other fishes.
HAGFISH; deeper water scvengers and parasites.

9. Lamprey