I'm guessing it's a cobweb spider, but most pics I found online showed light-colored legs, not dark like this girl. She has a dark brown abdomen with a light tan stripe along the front and 3 or 4 light tan triangles down the center of her back. Web was irregular, with a semi-transparent egg-sac about the size of her abdomen. Found in the basement in a dark corner; several bug carcases surrounding the web. Initially thought it was a black widow based on body shape and size, but abdomen is definitely dark brown with the only other color markings being light tan.