 The gastraphetes was a crossbow mounted on a stock divided into a lower and upper section.The lower was a case fixed to the bow while the upper was a slider which had the same dimensions as the case.Meaning "belly-bow", it was called as such because the concave withdrawal rest at one end of the stock was placed against the stomach of the operator, which he could press to withdraw the slider before attaching a string to the trigger and loading the bolt; this could thus store more energy than regular Greek bows.