In Canada there is only one member of the Viperidae family.    From Wordnik.com.  [Reptile families] Reference

Nicholas recognized cobras, kraits, puff adders, but there were all manner of Viperidae that he could not identify.    From Wordnik.com.  [Floating City]

Ontogenetic allometry in the fang in the front-fanged Causus rhombeatus Viperidae displaces the fang along the upper jaw.    From Wordnik.com.  [The Panda's Thumb: Development Archives] Reference

Triceratolepidophis sieversorum, a new genus and species of pitviper (Reptilia: Serpentes: Viperidae: Crotalinae) from Vietnam.    From Wordnik.com.  [Biological diversity in Indo-Burma] Reference

Then there are the Viperidae, rattlesnakes and pit vipers and copperheads, that also have front fangs, but phylogenetically belong to a distinct lineage from the elapids.    From Wordnik.com.  [The Panda's Thumb: Development Archives] Reference

The family Lacertidae, characterized by small, long-tailed lizards, is represented in the hotspot by more than 60 species, a quarter of the world total, while the family Viperidae, stocky venomous snakes, is represented by nearly 20 species.    From Wordnik.com.  [Biological diversity in the Mediterranean Basin] Reference

A New Long-Tailed Rattlesnake (Viperidae) From Guerrero, Mexico.    From Wordnik.com.  [Archive 2008-12-01] Reference

Crotalus and the Viperidae, and plenty of new (as far as my knowledge goes) saurians.    From Wordnik.com.  [More Letters of Charles Darwin — Volume 1] Reference

Family: Viperidae.    From Wordnik.com.  [Reptile] Reference

Family: Viperidae snakes commonly called vipers.    From Wordnik.com.  [CreationWiki - Recent changes [en]] Reference

Family Viperidae.    From Wordnik.com.  [Reptile families] Reference

2.6 Family Viperidae.    From Wordnik.com.  [Reptile families] Reference