पुराने विश्व वाइपर

viperidae's Usage Examples:

All the Viperidae are very poisonous and all, except the African Atractaspis, are viviparous.

Eyes free; with a pair of poison-fangs in the front part of the mouth, carried by the otherwise toothless, much shortened, and vertically erectile maxillaries; ventral scales transversely enlarged: Viperidae.

Maxillary vertically erectile, perpendicularly to ectoptery goid, and reaching quadrate or mandible: Viperidae.

Boulenger's phylogenetic system stands as follows: Viperidae Uropeltidae C. Opisthoglypha C. Proteroglypha Amblycephalidae mandible to the aglyphous or innocuous Colubridae, whence further differentiation in three new lines has taken place, - (i) the harmless Amblycephalidae as a side-issue, (2) the very poisonous proteroglyphous Elapidae, (3) the moderately or incipiently poisonous Opisthoglypha, out of some of which seem to have arisen the venomous Viperidae.

The Viperidae alone have "erectile" fangs.

viperidae's Meaning':

Old World vipers