ostropalean (adjective,ascus term) – with a thick tholus and opening by a pore; referring to asci that have a distinctly thickened tholus, but release their spores through a pore and not by extrusion. The ostropalean ascus is sometimes classified as a variation of the annular ascus, but has a distinctly thickened tholus instead of an annulus. Because of the tholus the ostropalean ascus can easily be mistaken for a lecanoralean or bitunicate ascus. However, spores are released through a pore instead of forcible "explosive" ejection by active discharge ("jack-in-the-box"). Kind of:ascus dehiscence type.