Lettering of the bones as in Fig. [3]
The principal modifications of the skull in the European genera may be contrasted as in the following synopsis:
I. Quadrate articulating with the cranium, supratemporal absent; mandible much shorter than the skull, with coronoid bone; maxillary small, on lower aspect of cranium; pterygoids not extending to quadrate; nasals forming long sutures with the premaxillary, prefrontals, and frontal
Typhlops.
II. Quadrate suspended from the supratemporal; mandible at least as long as the skull; pterygoids extending to quadrate or mandible.
A. Mandible with coronoid bone; nasals in sutural contact with frontals and prefrontals; transverse bone short, not projecting much beyond cranium; maxillary not half as long as mandible, which is not longer than skull (to occiput)
Eryx.
Fig. 7—Skull of Zamenis gemonensis. (From British Museum Catalogue of Snakes)