In 1853–6, when Mr. Sharpe published his monograph on the Cretaceous Cephalopoda of England, the various species were roughly placed according to the divisions of the Chalk formation as described by Conybeare and Philips. This, unfortunately, led to many mistakes: amongst others, Mr. Sharpe described Belemnitella mucronata as occurring “everywhere in the Upper Chalk of the South of England,” whilst Belemnitella quadrata is only noticed as occurring in the Middle Chalk of Kent, Surrey, and Sussex; the fact being that Belemnitella quadrata is not found in the Middle Chalk, and Belemnitella mucronata is restricted to the highest zone of the Upper Chalk.