Philodromidae picture from Wikipedia Commons 

Image: Wikipedia Commons.

Second pair of legs longer than the first pair.

Gives impression of a rectanguar turret.
Cephalothorax is a rounded triangle and may be wider than long. The prominence on which the eyes are found, in conjunction with the chelicerae can give the impression of a sort of rectangular solid having been added on top of the otherwise fairly regular convex oval shape.

Abdomen is spade shaped.