A and B are reconstructions (1843 and 1844 respectively) by <a href="https://en.wikipedia.org/wiki/Richard_Owen" class="extiw" title="w:Richard Owen">Richard Owen</a> who mistakenly believed that the phragmocone belonged to Belemnite that simply got separated from its guard (rostrum). They are therefore reconstructed as Belemnites.<br>
C is a restoration by Pearce (19th century, date unknown), the original describer of <i><a href="https://en.wikipedia.org/wiki/Belemnotheutis" class="extiw" title="w:Belemnotheutis">Belemnotheutis</a></i> who, like Gideon Mantell, believed that <i>Belemnotheutis</i> was a distinct belemnoid from true belemnites.
<a href="https://en.wikipedia.org/wiki/Richard_Owen" class="extiw" title="w:Richard Owen">Richard Owen</a> and J.C. Pearce
<i><a rel="nofollow" class="external text" href="http://palaeontology.palass-pubs.org/pdf/Vol%2035/Pages%20273-296.pdf">The Type Material of the Jurassic Cephalopod Belemnotheutis</a></i> by D.T. Donovan and M.D Crane