A. Coronoid present; nasals in contact with prefrontals.
1. Vestiges of pelvis; supratemporal present.
Supratemporal large, suspending quadrate
3. Boidæ.
(Subfamilies: Pythoninæ, Boinæ.)
Supratemporal small, intercalated in the cranial wall
4. Ilysiidæ.
2. No vestiges of pelvis; supratemporal absent
5. Uropeltidæ.
B. Coronoid absent; supratemporal present.