92 DR ROBERT KIDSTON ON THE 



Horizon and Localities. — 



Ten-foot Ironstone Measures : Clayscroft Openwork, Coseley, near Dudley. 

 Roof of New Mine Coal: Mount Pleasant, Brierley Hill. 

 Roof of Fireclay Coal: Doulton's Clay Pit, Netherton. 



Zeilleria Kidston. 

 Zeilleria Avoldensis Stur., sp. 



PL VII. figs. 5, 5a, 5b, G, 6a. 



1878. Fhtinophyllum Avoldense, Stur, Verh. d. k. k. geol. Reichsanstalt, p. 213. 



1883. Calymmotheca Avoldensis, Stur, "Morph. u. Syst. d. Culm- u. Carbonfarne," Sitzb. d. k. Akad. d. 



Wissensch., vol. lxxxviii. p. 171, fig. 37. 

 1885. ,, ,, Stur, Fame d. Carbon-Flora d. Scliatzlarer Schichten, p. 251, 



pi. xxxvii. fig. 1, text-fig. 41, p. 238. 

 1899. ,, „ Potonie\, Lehrb. d. Pflanzenpal., p. 103, fig. 90 i. 



1884. Zeilleria Avoldensis, Kidston, Quart. Journ. Geol. Soc, vol. xl. p. 591. 



1887. ,, ,, Kidston, Trans. Roy. Soc. Edin., vol. xxxiii. p. 148, pi. viii. figs. 8-10. 



Description. — Frond very large quadripinnate. Primary pinnae broadly 

 lanceolate ; secondary pinnae alternate, linear-lanceolate ; tertiary pinnae alternate, 

 linear-lanceolate, or oblong lanceolate. Pinnules alternate, attached by their whole 

 base to the rachis and united to each other for one-third to two-thirds of their length ; 

 free portion of limb ovate triangular. Nervation clearly defined, and consisting of a 

 central vein which generally gives off a lateral veinlet on each side, which extends to 

 the margin of the pinnule. 



Fructification apparently confined to the tertiary pinnse on the lower secondary 

 pinnse, where the fertile pinnules, similar in form to the sterile ones, bear one to three 

 pedicellate cupule-like structures placed at the extremities of the excurrent veins. 

 When immature the fructification appears as a closed oval structure, but at maturity 

 it splits into four, rarely into five, spreading segments, which on the specimens with 

 larger cupules show in the centre a small mammillate point to which a small organ, 

 presumably a seed, has been attached. What are probably the microsporangia are 

 very similar in form to the seed-bearing cupules when unopened, but are of smaller size. 



Remarks. — Two specimens of this fern are given on PI. VII. figs. 5, 6. That given 

 natural size at fig. 6 represents fairly well the general character of a fertile specimen, 

 though the structure of the fructification is not well exhibited. A small portion of 

 the same specimen is shown enlarged 2 times at fig. 6a. Most of the sporangia seem 

 to have adhered to the counterpart of the specimen, which unfortunately has not been 

 preserved. They are much better seen on another small example, also from the South 

 Staffordshire Coal Field, which has already been figured in vol. xxxiii., pi. viii. figs. 

 8-10, of the Transactions of this Society. Here the small cupule-like structures are 

 seen to be oval when immature, but split at maturity into four valves about 1 mm. 



