Imatthew] upper devonian PLANTS 113 



"Hitherto no Gymnosperms have been seen in the Kiltorcan 

 deposits. Illustrations on Plate IV, Figs. 3 and 5, are representations 

 of the form found at Kiltorcan that represent the genus Ginkgophyl- 

 liim. 



Le.a-F (or Leaflet) (Plate IV, Fig. 3.) 



"This object is 7 cm. long and 5 cm. wide. In general outline 

 it is fan-shaped, gradually tapering to form a ribbon-like petiole 

 25 m.m. long and 2-5 m.m. wide. The leaf blade is symmetrical and 

 divided into two lobes, and each of these again into two, themselves 

 divided into ribbon-like segments, the whole more or less palmately 

 lobed; eight lobes in all. Venation clearly dichotomous: petiole 

 traversed by four veins in the upper part; these fuse downward in 

 pairs and form the double leaf-trace, so characteristic of Ginkgo 

 and primitive Gymnosperms. The venation agrees, as far as trace- 

 able, with Ginkgo biloba. 



The disappearance of lobation is in keeping with the general 

 conclusion of the fossil evidence, viz.; that the earlier types, Baiera, 

 show more deeply lobed leaves, and that later (Mesozoic passed into 

 Tertiary) the normal wedge-shaped, simply-lobed, or unlobed, long- 

 stalked leaf of the extant Ginkgo (to the final exclusion of the seg- 

 mented type) predominated. 



"Ginkgophyllum Kiltorkense and Psygmophylliim Williamsoni 

 are then the earliest known leaves of the Ginkgoaceae, and of interest 

 as showing the occurrence of this group of Gymnosperms in the 

 Devonian epoch, i.e. as early as the Cordaietaceae. 



"Another instructive fossil now known as a Ginkgophyte under 

 the name of Trichopitys, was described by Renault as Dicranophyllum 

 gallicum. In it the leaf scars are close together, without any interven- 

 ing stem surface, and are Lepidodendroid, as shown by Renault's 

 figures; in this species the leaves are filamentous and forked. 



Fruit (Plate IV, Fig. 5.) 



"Stalked bodies of the same size and shape as the Heterangium- 

 like seeds of the Carboniferous sandstone of Scotland, described by 

 Gordon, have been found ; but are not certainly the seeds of this plant. 



HiMANTOPHYTON. 



The above genus was proposed by the writer to contain remains of 

 a plant found in the Silurian rocks of Beaver Harbor in New Bruns- 

 wick, Canada, it having been found to differ from any hitherto des- 

 cribed form. A species of this genus so far as can be decided from the 

 prostrate and upright part of the vegetative portion of the plant, was 



Sec. IV, Sig. 8 



