It is patchily or discontinuously distributed, with the patches separated by faulting. Columbian ground squirrels live in colonies distributed discontinuously throughout their range. The fires burned discontinuously, leaping from one patch to another, leaving intervening areas untouched. They were reported discontinuously distributed in low numbers. The Kanichee Mine zone has been explored and mined discontinuously from as early as 1910. It is discontinuously distributed in the deserts of the Arabian peninsula and the Middle East. The range of the dusky shark extends worldwide, albeit discontinuously, in tropical and warm-temperate waters. These four boats, discontinuously numbered, were built by Thornycroft to a common design. Bianca Maria and her husband initiated a new dynasty that ruled Milan discontinuously until 1535. Its range extends east to the Rocky Mountains and discontinuously to the Great Lakes Region. The World Bank reported in 2009 that the three existing wastewater treatment plants work discontinuously. They are found discontinuously to Greece, Turkey and throughout the central Middle East. Areas above the timber line appear discontinuously as "islands" in the Sudetes. The addition or removal of material may discontinuously change the boundary of the object. The products of the Boring Lava Field were erupted discontinuously over an erosion surface.