| Protochordates:- 
 Balanoglossus: Tornaria larva Ascidia: Retrogressive metamorphosis | 
Amphioxus
| Agnatha:- 
 Petromyzon | 
Ammocoete larva
| Gnathostomata 
 Scoliodon 
 | 
Economic importance of Fishes
| Amphibia 
 Reptilia 
 | 
Poisonous & Non-poisonous snakes
Poison apparatus
| Aves 
 Mammals 
 | 
Hair and its development