174 Scientific Proceedings, Royal Dublin Society. 



have been. Indeed as I first read Saporta's account of Ginkgophyllmn 

 Grasseti, the type of his genus, I was much struck by its general agreement 

 with the Irish specimen, which I propose accoi'dingly to name Ginlmophi/Uum 

 kiltorliense. 



GinhjoplujUum I'iHorkeHse and Psygmophyllwn WiUiamsoui (if we regard 

 the latter, as Nathorst is inclined to do, as a Ginkgophyte) are then the 

 earliest known leaves of the Ginkgoacese, and are of interest as evidence of 

 the occurrence of this group of Gymnosperms in the Devonian epoch, i.e., 

 at as early a period as that of the CordaitaceBe. In the slab whicli 

 yields this leaf of Ginlcgophyllimi kiltorkense there are other fossil impressions 

 deserving notice. One of these is indicated at [a] in PI. X, figs. 1 and 2, 

 and magnified in PI. XI, fig. 5. It appears to be a small detached piece 

 of flattened stem folded on itseU', 30 mm. long and 4 mm. wide. It is mainly 

 interesting because it shows over its surface oval erect scars arranged in 

 ascending spirals. The scars are 1'75 to 2 mm. long and 1 mm. wide. In 

 each one can see a central straight dark line running the greater part of 

 the length of the scar. The line ceases at a little distance from tlie more 

 pointed end of the scar and leaves a clear space in it, though occasionallj' 

 one may see signs of a dot-like speck in this space. The scars are, I take it, 

 leaf-scars ; and so far as arrangement and distance from one another (2 mm.) 

 are concerned remind one of a Bothrodendron-like stem. The scars are not 

 like those of this genus and are new to me. The general external surface of 

 the stem is finely striate longitudinally (PI. XII, fig. 1). 



It is worthy of note that the leaf-scar is the same in length — 2 mm. — 

 as the width of the petiole of the associated leaf. On another slab is a 

 fragment of stem bearing a small wedge-shaped leaf which suggests itself as 

 the young leaf of Ginkgophyllum kiltorkense (PI. XI, fig. 2, a). This leaf is 

 inserted in a flattened vertically elongated base, i.e. as one would expect 

 it to be if the stem and leaf-scars described, together with the leaf of 

 G. kiltorkense, belong to the same adult plant. The figures wliich 

 Fontaine (11) gives of the foliage shoots of Baiera (Baieropsis), e.g. 

 B. adiantifolia and B. foliosa, show wedge-shaped leaves with vertically 

 elongated bases of insertion, i.e. lobed, fan-shaped leaves of upright habit, 

 so that stem and leaves look like a pinnate leaf. 



Baiera foliosa Font, is a Ginkgophyte which occurs in the Mesozoio rocks 

 of Europe aud America. As quite recently redescribed by Berry (12), the 

 plant possesses dwarf shoots or spurs like those of Ginkgo and stalked lobed 

 leaves with the usual Baiera characters, arranged in a low spiral. The leaf- 

 bosses are rounded, sub-rhomboidal, 2 mm. apart. 



