L 245 J 



v\ 



XXIII. 



SPEBMOLITHUS DEVONICUS, gen. et sp. nov., AND OTHER 

 PTERIDOSPERMS FROM THE UPPER DEVONIAN BEDS 

 AT KILTORCAN, CO. KILKENNY. 



By THOMAS JOHNSON, D.Sc, F.L.S., 

 Professor of Botany in the Royal College of Science for Ireland, Dul 



(Plates IX-XIV.) 



Read Junk 26. Published August 20, 1917. 



The realization of the existence of the Pre-Tertiary group of Cycadofiliees, 

 and the discovery of several genera of the group with attached seeds 

 leading to the segregation of such, as the Ptcridospcrms (1), added con- 

 siderable interest to the re-examination of the material collected from the 

 Upper Devonian (Yellow Sandstone) beds of Kiltorcan, Co. Kilkenny. 

 Beautiful large stipulate fronds of Archaeopteris hibemica Forbes sp., both 

 sterile and fertile, have been known since 1846 (2). In 1911 the presence 

 in the Kiltorcan deposits of Archaeopteris Tschermaki Stur., previously known 

 only from the Culm of the Continent, was noted (4). The Irish specimen 

 shows signs of the bifurcation of the frond seen in Sphenopteridium Schimper, 

 to which A. Tschermaki has been transferred. Gothan (5), writing in 1913, 

 considers this genus, partly on account of the appearance of transverse striae 

 or sclerotic bands in its rachis, to be a Pteridosperm, allied to Heterangiwm. 

 The specimen of S. (A.) Tschermaki found at Kiltorcan was in a fertile state, 

 showing a sporophyllule, indistinguishable as an impression from that of 

 typical Archaeopteris hibemica. This latter species was for a long time after 

 its discovery natura'ly regarded as a fern, and the small stalked spindle- 

 shaped bodies of the fertile fronds as its sporangia (3). For six or seven years 

 past I have examined a great deal of material (quarried for road-repairing at 

 Kiltorcan !) (4) in the hopes of finding something more than the isolated fronds 

 known up to the present. I had hopes, too, that seeds might be unearthed, 



SCIENT. PEOC. K.D.S., VOL. XV., NO. XXIII. 2 E 



