ROLL CALL jqs 



PHYLUM XIII — CHORD ATA — Animals with notochord. 



Characteristics: All possess a dorsal supporting rod or notochord and 

 pharyngeal gill clefts at some stage in life cycle; tubular nerve cord 

 dorsal to digestive tract ; 36,000 species. 



Sub-Phylum I — Hemichordata — (Balanoglossus). 



Characteristics : Wormlike marine oiganisms of doubtful relationship that 

 burrow in sand and resemble the larval echinoderms in development ; head- 

 end with proboscis and collar; with or without a notochord. 



Sub-Phylum II — Urochordata — Tunicates and ascidians. 



Characteristics : Marine organisms with saclike covering {tunic) ; larvae 

 resemble tadpoles, possessing notochord in tail; gill slits and endostyle 

 present in pharynx. 



Sub- Phylum III — Cephalochordata — Lancelots (Amphioxus). 



Characteristics : Segmented primitive chordates, burrowing in sand ; lat- 

 erally compressed ; notochord extending from anterior tip to tail. 



Sub-Phylum IV — Vertebrata (or Craniata) — Vertebrates. 



Characteristics : Animals with definite head, sense organs, closed circula- 

 tory system, and axial notochord at some period in life cycle; skull and 

 vertebral column present either in cartilaginous or bony stage. 



Super-Class A — Agnatha — Fossil, armored Ostracoderms, lampreys and hag- 

 fishes (Cyclostomata). Primitive fishlike forms (Pterichthys, Petromy- 

 zon). 

 Characteristics: Animals w'ithout jaws; sucking mouth and primitive 

 brain present. 



Super-Class B — Pisces — True fishes. 



Characteristics : Organisms with true jaws ; typically scaled ; charac- 

 teristically aquatic; appendages developed into fins; two-chambered 

 heart. 



