Two pairs of detached fossil cupules from the Cementstone Group of the East Lothian coast are described. One pair (specimen 1) contains 16 ovules agreeing with the seed genus Hydrasperma Long as well as 8 microsporangia containing spores. The second pair (specimen 2) has neither ovules nor microsporangia.

The ovules present in specimen 1 have about 9 free apical tentacles and as many longitudinal ridges on the bodies of the ovules. The central column is very well developed, about as long as the ovule body and obconical in shape. In it some of the cells have bars of thickening on the walls like transfusion cells. Each cupule-pair has a common stalk which divides to become the two inverted cupules. In specimen 1 each cupule has a wall consisting of two valves united above but subdivided into tapering lobes below, i.e. distally. Ovules are borne below the concave upper region of each cupule (sessile laminar placentation). In this specimen each cupule-valve is subdivided into two smaller portions, one of which bears 8 microsporangia. The latter appear to be terminal and reflexed and almost sessile.

The laminar placentation in Hydrasperma supports the view that this type of placentation in angiosperms is primitive and the bisexual cupule-pair here described suggests that the primitive fertile fronds from which cupules (and presumably carpels) evolved were originally capable of bearing both mega- and microsporangia.

Four new petrified specimens of cupules assigned to Hydrasperma cf. tenuis Long are described from the Cementstone Group of Oxroad Bay, East Lothian. In one of these specimens four ovules are present. Three of the specimens are interpreted as representing a pair of cupules derived from a single megasporophyll showing dichotomy so that each cupule is termed a hemi-cupule and has two lobed halves which represent quarters of the entire megasporophyll. In the fourth specimen five cupules are present, each possessing two lobed halves not sub-divided into quarters. Hydrasperma is thus interpreted as showing two kinds of cupules designated mega-cupules and paired hemi-cupules. The theory is developed that angiosperm carpels have evolved from the two kinds of pteridosperm cupules.

Mitrospermum bulbosum sp. nov. is described from a single specimen found in the Lower Carboniferous Cementstone Group of Berwickshire. It is a platyspermic seed about 14 mm diameter. The nucellus is free from the integument laterally and contains a single megaspore above which is a pollen chamber and well-developed apical beak. The integument is cordate at the base around a bulbous chalazal region with two membranous wings which terminate above as two flat lobes having a V-shaped sinus between. At the base of this sinus is the micropyle which surrounds the apex of the nucellar beak.

Mitrospermum compressum Arber has been re-investigated from 21 specimens and evidence adduced to show that the micropylar canal expands upwards and opens between two short apical lobes.

Conostoma oblongum Will, has been re-investigated from 20 specimens. It possesses four integumental bundles; sometimes there are two basal lobes but no integumental flanges; no free apical lobes have been seen and the seed was sessile, not having a wide pedicel.

A specimen of Lagenostoma ovoides Will, with a mature prothallus is briefly described from longitudinal sections. At the upper end the prothallus has three archegonia and a circular trough surrounding the ‘tent-pole’.