[c₁]/[m₁] diagram for likely members of NGC 2345. The black lines represent the standard relation from Perry et al. (1987) for B stars (dashed line), A stars (solid line), and F stars (dotted line). B and Be stars observed spectroscopically are shown as blue circles and magenta diamonds, respectively. Green circles indicate those stars selected as B-type among all of the remaining members (grey dots).