The marbled cellar spider (Holocnemus pluchei) has long, skinny legs and a dark stripe along its abdomen, accompanied by a marbled pattern. It's considered an urban pest because it's often found making flimsy webs on the ceilings of homes. You will almost never see its eggs because it carries the egg sacs around in its fangs.

Specimens of both sexes have a body length of 8–11 mm. Their first pair of legs is roughly 6.5 times the length of the body.

As in other spiders, male is smaller than female which is 7 mm in average length. The species has a cylindrical and elongate abdomen. The purple spots along the dorsal surface if the abdomen is the characteristic feature. There is a dark stripe in the ventral surface of sternum. A synanthropic spiders, it builds irregular cobweb in sheltered areas to capture small insects and other spiders for food. Legs without spines, few vertical hairs can be seen. Female has a simple epigynum without pockets.

The box spider can most often be found inside or around the outside of human dwellings. They can be beneficial for pest control but they do not eat their old webs like most spiders, leaving many old ones around houses. They can also rub together plates and ridges on two areas of their bodies to produce a sound.