6 Scientific Proceedings^ Royal Duhlin Society. 



der Ablageruug dreier (lll-V) Flotzgruppen der Ostrauer Schichten sicli 

 gleichblieb. 



" Es f allt somit bier zwischen jenem momentanen Zustand des Typus, den 

 ich als Calynmiotheea Stangeri tezeicbnet babe, uud dem naolist jungeren, die 

 Cah/mmotheca Hdninghausi, jene Liicke, die zwischen der Ablagerung der 

 Ostrauer Schichten und der Scbatzlarer Schichten besteht. In diese fallt die 

 Vollbringung der grossten bemerkbaren Verschiedenheit zwischen den beiden 

 genannten Pflanzenresten, d.h. wahrend der Dauer dieser Zeitliicke muss die 

 Veranderung der C Stangeri in die C. Honiiighmm stattgehabt haben." 



Tims Stur mentions three species — C. Falkenhaini, C. Stangeri, 

 C. Hmingliausi, which gradually change in the order named from one to 

 the other in the ascending Culm strata— and states that they are all so closely 

 allied as to be really not more than varieties of one and the same type, 

 thougli he gives them specific names. They only differ in the gradual, 

 scarcely perceptible elongation of the pinnule segments. As C. Hdning- 

 hausi — i.e. S. Hdninghausi — -is, we know from Kidston, the foliage of Lygino- 

 dendron, the transition from C. Stangeri to it is slight, and the identification 

 of C. Stangeri, with its iudusial lobes, as the fertile but seedless frond of 

 Lyginodendron is amply justified. 



Recently, in the course of rearrangement of the collection of fossil 

 plants in the Botanical Division of the National Museum, my first object 

 was to see to what extent the newly founded group of the Pteridospermese 

 was represented in the collection. I first of all examined all the forms of 

 SphenojJteris, and especially two specimens which were labelled with a query, 

 Sphenopteris Hdninghausi, from the Coal Measures of Glengoole, County 

 Tipperary. The different forms of Sphenoj^tcris were compared with those in 

 the collection of the Geological Survey of Ireland, also housed in the National 

 Museum, and under the charge of Professor Grenville Cole, Director of the 

 Survey. As the result of a detailed comparison, I came to the conclusion 

 that the two specimens of Sphenopteris just mentioned were true S. Honing- 

 lunisi; and in one of them I saw characters of a fertile condition suggestive of 

 the described characters of Calymmatotheca Stangeri. In a specimen of 

 Sphenopteris Hdninghausi in the Geological Survey collection the C. Stangeri 

 condition was unmistakably present (Plate I., fig. 1). The specimen presents 

 a further feature of interest. Not only are the indusial lobes observable, 

 but in the midst of these, at one point certainly, and at other points 

 doubtfully, one can see, with a magnification of 45, every indication that 

 a seed is present. Thus we have here, so far as one may judge from a 

 carbonized impression, if my interpretation is correct, that direct con- 

 tinuity between the vegetative organs of Lyginodendron oldhamiiun, the 



