Long-jawed Orb Weavers are named because of their large chelicerae (fangs), which are, in some species, longer than the spider's cephalothorax (the fused head and thorax of spiders). This family and another one called true orb-weavers are the only kinds of spiders that make orb webs. The webs of most other kinds of spiders appear disorganized compared to orb webs.
Spiders like todays species (Tetragnatha laboriosa) build their webs in strategic locations to catch flies, moths, and other insects. Birds and other small animals often eat these kinds of spiders. They are very common in tree branches that overhang lakes and streams. Often, a long-jawed orb weaver will remain still in its web so that you can take a good picture. If you are interested in collecting one of these spiders, remember that they can bite and should never be handled, although they aren't typically dangerous.