Grass spiders may be recognized by the arrangement of their eight eyes into three rows. The larger specimens (depending on species) can get up to approximately 19 mm in body length. The top row has two eyes, the middle row has four eyes, and the bottom row has two eyes (spaced wider than the ones on the top row). They also have two prominent hind spinnerets, and somewhat indistinct bands on their legs. They also have two dark bands running down either side of the cephalothorax.
Grass spiders are a type of funnel web spider, that lives hidden in webs they build in grassy areas. It's easiest to see them in the early morning when they're most active, and not hiding in their tunnels. This spotting was done at the Bolsa Chica Wetlands, an estuary and bird sanctuary located next to the Pacific Ocean.
These spiders are harmless to humans, with Chilicerae that cannot penetrate human skin. They are fast running, because that's how they catch their prey, and so can be startling! The 13 individual species are very similar in appearance, so only an expert should try to identify beyond genus.