CONTRIBUTIONS TO OUR KNOWLEDGE OF BRITISH PALAEOZOIC PLANTS. 713 



but, as the interfoliar area elongates, the leaf scars and cushions assume the form of 

 Sigillaria Fannyana Weiss,* which can only be regarded as a form of Sigillaria 

 elegans. 



Locality. — Stein's Fireclay Works, f mile north-east of Castlecary Railway 

 Station, Stirlingshire. (PI. II, figs. 1-4 ; PI. Ill, fig. 4.) 



Horizon. — Upper part of Millstone Grit, Lanarkian Series. Collected by Mr D. Tait. 



Locality. — Shell Brook, branch of river Dane, near Mareknowles, fully I mile 

 north of Barghleighford, North Staffordshire. (PI. Ill, fig. 8.) 



Horizon. — Below Fifth Grit, near base of Millstone Grit. Lanarkian Series. 

 Collected by Mr D. Tait. 



Sigillaria incerta, n. sp. (PI. II, figs. 5, 5a, 6, 7 ; PI. Ill, figs. 5, 5a.) 



1894. Sigillaria Brardii, Kidston (non Brongt.) (pars), Proc. Roy. Phys. Soc. Ed., vol. xii, p. 252. 



Description. — Sigillaria showing arrangement of leaf cushions intermediate 

 between Favularia and Clathraria sections. Vertical rows of leaf cushions separated 

 by a very strongly marked zigzag furrow. Cushions hexagonal, or rounded hexagonal, 

 sometimes with feeble notch on the upper margin, resting on each other above and 

 below for about one-third of their width, with prominent lateral angles, smooth. 

 Leaf scar occupying almost the entire surface of the cushion or having a greater or 

 less portion of the cushion prolonged beyond its lower margin, rounded above, lower 

 margin rounded or ending in a point ; lateral angles prominent. Cicatricules placed 

 slightly above the centre, middle one (the vascular bundle scar) punctiform, the 

 lateral (parichnos) slightly elongated. 



The cone scars form a verticil of one row deep. 



Remarks. — An impression of a specimen of this species is shown natural size on 

 PI. II, fig. 5, and a portion is enlarged two times at fig. 5a. The Favularian arrange- 

 ment of the leaf scars is clearly seen on the upper portion of the fossil, though at the 

 central part their distribution approaches to that of the Clathrarian section. To- 

 wards the centre of the fossil is part of a verticil of cone scars, arranged in a single 

 row. The leaf scars are subhexagonal with prominent lateral angles equidistant from 

 top and bottom of the scar. The three cicatricules are placed slightly above the 

 middle, the central punctiform, the two lateral elongate, converging to or diverging 

 from each other. Immediately below the cone verticil (fig. 5a) the leaf scars 

 occupy almost the entire cushion, which only forms a very narrow border — a border 

 probably representing the elevated sides of the cushion before it was compressed. 

 At the upper and lower ends of the fossil the cushion below the leaf scar is slightly 

 elongated and the leaf scar occupies its summit, the lateral angles of which join the 

 margin of the cushion some little distance above its lateral angles. These elongated 

 cushions are hexagonal, smooth, and only rarely show indications of two diverging 

 ridges from the base of the leaf scar. 



* Weiss, I.e., p. 35, pi. (5) xi, figs. 51 and 52. 



