The hypothecium is the basal part of the apothecium on which the hymenium is borne; the latter consists of asci (thecae) with ascospores, and paraphyses.
B, Asci (thecae) with bilocular spores.
There is a tendency for the branches to become reduced in number, and for the serial thecae to become directed more and more upwards towards the line of the nema.
The thecae uniserial (monoprionidian) - t here is a gradation from earlier groups with many branches to later groups with only two; and from species in which all the branches and' their thecae are directed downwards, through species in which the branches become bent back more and more outwards and upwards, until in some the terminal thecae open almost vertically.
The Monograptidae, the branches are theoretically reduced to one, the polypary is uniserial throughout, and all the thecae are directed outwards and upwards.