Johnson — A Seed-Bearing Heterangium from Co. Cork. 251 



The slab on both sides shows scraps in which I have sought in vain for 

 signs of pinnse. In fig. 2 one sees a forked scrap in connexion with a branch 

 of the raohis, and ending in its curved tips in dilatations not unsuggestive 

 of seeds. The clearest case is that represented in fig. 3. A branch of the 

 rachis (Fig. 2, a) bears a small curving rachidial filament on which, in 

 addition to one or two finer branches and lateral expansions, an oval body 

 is carried at its tip. This sessile body, 2 mm. long and 1 mm. wide, shows 

 a central space or cavity bordered by a wall of fairly uniform thickness, 

 slightly papillate at the apex. It is continuous with the rachis branch, and 

 appears to be an immature ovule or seed, of less size than an ordinary 

 Conostoma (10) seed, but of the same general " boat-like " form. It is 

 unfortunately only an impression ; and I must leave the illustrations (PI. XX., 

 figs. 2, 3) to support me in concluding that it supplies additional proof 

 that Heterangium, like Lyginodendron, is a true Pteridosperm. In this 



Fig. 2— Cf. PI. XX., fig. 2. 



Fig. 3 — Shows the " ovule" 

 borne on a branch of the 

 rachis. 



connexion the following note from the columns of " Nature " on a paper 

 read by Dr. Margaret Benson (12), March, 1909, is of interest. So far as I 

 know it is the only information yet published on the investigation : — 



" Sphwrostoma ovale, n. gen., and Crossotheca Grievii, n. spec, an account 

 of the structure and relations of the reproductive organs of Heterangium 

 Grievii. 



" Sphcerostoma ovale [Conostoma ovale et intermedium, Williamson) is the 

 earliest Palaeozoic ovule so far known structurally. It is a small ovule 

 3-5 mm. in length, and shows the same general type of orgauization as the 

 ' Lagenostoma ' series of ovules. The pollen-chamber, however, does not 

 engage with the micropyle, but opens and closes with a very perfect 



