lots of 404 not found error

hi i get lots of 404 error in the google webmaster tool here is the screenshot dont wr is the problem few days bfore removed lots of link i removed in sitemap itself and also resubmitted tat sitemap in google itself but still get 404 error for tat removed url how can i solve this?

here i get one solution from oleg Google crawling non-existent pages & getting confused wat abt the internal links i mean removed url