218 MR ROBERT KIDSTON ON 



This is one of those forms which stands intermediate in character between Sphenop- 

 teris crenata, L. and H., and Pecopteris plumosa, Artis, and which it is very difficult to 

 refer to either one or the other, but, in its general aspect, it has perhaps a greater 

 similarity to Sphenopteris crenata. The rachis is roughened with small points. 



On the ultimate pinnse the inferior basal pinnule is very small and composed of two 

 lobes, — a larger subtriangular one, with a smaller lateral rounded lobe next to the main 

 rachis. The basal superior pinnule is longer than the succeeding pinnules, and on the 

 lower pinnae bears several pairs of rounded lobes (fig. 125). The corresponding pinnule 

 on the upper pinnse bears a few lobes at the base (fig. 12a). A central vein gives off 

 lateral veinlets to each lobe. 



PI. II. fig. 14x28. 



From Monckton Main Colliery, near Barnsley, Yorkshire. Horizon. — Barnsley Thick 

 Coal. Middle Coal Measures. 



This figure shows a few sporangia magnified 28 times, from another specimen 

 belonging to the Sphenopteris crenata form of the same species. This specimen shows 

 how the sporangia are placed on the pinnules. Each of the small lobes had a row on 

 each margin, the sporangia lying at right angles to the midrib. Thus, in fig. 14, the 

 central vein ran between the two rows marked a' and a", but most probably the spor- 

 angia were placed on lateral veinlets, which sprang from this central vein, and which 

 have now disappeared. I think this is shown from the nervation preserved in figs. 11a 

 and 116, pi. iii. 



The sporangia drawn show some groups from which all trace of the limb has been 

 removed, and which have probably adhered to the counterpart of the block containing 

 the fossil, thus leaving only the sporangia attached to the matrix of the specimen in my 

 possession. 



The sporangia, which are beautifully preserved and show well the cell structure, are 

 oval in form, and measure on an average about 0'50 mm. in length. They are absol- 

 utely devoid of all trace of an annulus. Had an annulus been present even in a most 

 rudimentary form, from the excellent state of preservation of the sporangia on this and 

 on several other examples in my possession, it could not have escaped observation. 



The sporangia on all my specimens are more oval than those described by Zeiller in 



the Flore foss. Bassin houil. de Valenciennes, pi. xxvi. fig. 2, and in the Ann.d. Scienc. 



Nat, 6 e ser. ' Bot.', vol. xvi. pi. ix. figs. 12-15, 1883, but they agree in form with those of 



his Dactylotheca dentata, var. obscura* The general character of Zeiller's fig. 2, pi. ii., # 



in the copious manner in which the sporangia have been produced and the absence of 



the limb, shows a great resemblance to such specimens as those figured on my pi. ii. 



figs. 5, 7, and 14. 



PI. II. figs. 9, 9a, 96, and 9c. 



From Monckton Main Colliery, near Barnsley, Yorkshire. Horizon. — Barnsley 

 Thick Coal. Middle Coal Measures. 



* Flore foss. Bassin houil. et perm, de Brive., p. 26, pi. ii. figs. 2, 2a, 26, aud 2c. 





