398 MR ROBERT KIDSTON ON THE FOSSIL FLORA OF THE 



referable to typical Sig. tessellata, especially as figured by Zeiller (loc. cit., pi. 

 clxxiii. fig. 2). 



It seems probable that Sig. elegans and Sig. Knorrii are at the most only 

 varieties of Sig. tessellata, and Schimper * would not only unite these with Sig. 

 tessellata, but many other so-called species, and in the Catalogue of Palaeozoic 

 Plants in the British Museum, I follow him in placing a number of species 

 under Sig. tessellata. Some botanists, however, regard many of these plants 

 as specifically distinct from Sig. tessellata. Zeiller places considerable value 

 for specific distinction on the disposition of the cone scars. According to this 

 author, in Sig. tessellata they are placed in the bottom of the furrows separat- 

 ing the ribs, and are of rounded or quadrangular contour, placed in vertical 

 parallel rows, and encircle the stem in a band of about equal width. In Sig. 

 elegans, on the other hand, the scars are said to be larger, sometimes assuming 

 a quadrangular or polygonal contour, and occur on the ribs as well as in the 

 furrows that separate the ribs, and form a band of scars in vertical series, 

 but the series are not so long as in Sig. tessellata.^ 



Examples of Sig. tessellata showing verticels of cone scars are frequently 

 found at the localities here mentioned for the species. 



Bifurcating branches of Sig. tessellata are rare, but lately I have seen two 

 specimens — one from Camerton in the collection of Mr George West, and 

 the other from Bardsley, Ashton-under-Lyne, Lancashire, in the collection of 

 Mr George Wild. 



Localities : — Radstock ; Braysdown Colliery ; Camerton. 



Sigillaria laevigata, Brongniart. 

 Plate XXVIII. fig. 5. 



Sigillaria laevigata, Brongt., Hist. d. veget. foss., p. 471, pi. cxliii. 

 Sigillaria laevigata, Kidston, Catal. of Palaioz. Plants, p. 193 (excl. syu. S. ovata). 

 Sigillaria laevigata, Zeiller, Veget. foss. du terr. houil., p. 125; Flore foss. d. Bassin houil. de 

 Valenciennes, pi. lxxviii. figs. 1-4. 



Description. — Stem furrowed, furrows straight, ribs smooth, leaf-scars more 

 or less distant, oval, narrowed upwards, higher than broad, or height about 

 equal to width, lower and upper margins rounded, lateral angles distinct, from 

 which extend downwards two raised lines that reach the scar immediately 

 below or vanish a little above it. Vascular cicatricules situated above the 

 centre of the scar, — lateral linear, central transversely oval. A short distance 

 above the leaf -scar is usually placed a small cicatricule. 



Decorticated stems, striated, lateral vascular cicatricules linear-reniform, 

 increasing much with age, and becoming confluent. 



* Traite d. paleont. veget., vol. ii. p. 81. 



f Zeiller, Ann. d. sc. nat. Bat., 6 e se>., vol. xix. p. 275. 



