Brown Recluse

Brown Recluse Spiders are usually between 6-20 mm (1/4 in and 3/4 in), but may grow larger. It is brown and sometimes an almost deep yellow color and usually has markings on the dorsal side of its cephalothorax, with a black line coming from it that looks like a violin with the neck of the violin pointing to the rear of the spider, resulting in the nicknames fiddleback spider, brown fiddler or violin spider. Coloring varies from light tan to brown and the violin marking may not be visible. Source: Wikipedia.com