FOSSIL FLORA OF THE STAFFORDSHIRE COAL FIELDS. 329 



Remarks. — Though the leaf scars of Sigillaria mamillaris are variable in the propor- 

 tion of their length to their breadth, it is an extremely well- characterised species. The 

 gradual elevation of the leaf scar from above downwards affords a character by which it 

 is distinguished from several named forms, some of which are, however, most probably 

 Sigillaria mamillaris in a different state of preservation. 



Of these may be specially mentioned Sigillaria pyriformis, Brongt. , which does not 

 appear to differ in any essential character, except that the leaf scars are horizontal with 

 the surface of the ribs — a distinction arising in all likelihood from pressure. Sigillaria 

 pyriformis is therefore united here with Sigillaria mamillaris. 



Other very close allies are Sigillaria elliptica, Brongt.,* and Sigillaria notata, 

 Steinhauer, sp.t 



This latter species differs chiefly in the leaf scars being of less width than the breadth 

 of the ribs. Steinhauer's example came from the coal pits of Dunkerton, Somerset, 

 which are now closed. I have, however, searched in Somerset for specimens of Sigillaria 

 that could be referred to Sig. notata, Steinhauer, in shales associated with coals on the 

 same horizon as that from which the original specimens came, but without success. 



The specimen of Sig. notata, figured by Brongniart, came from Anzin, near Valen- 

 ciennes,} and Boulay remarks § — " Brongniart indicates this species from Anzin. T 

 have collected very well-characterised specimens of it at the pit of Petite-Sorciere, near 

 Jemmapes (Belgium). This plant, which Brongniart regarded as allied to Sigillaria 

 elliptica, is more closely allied to Sigillaria mamillaris, of which it might well be only 

 a condition or a fragment." 



The question whether Sig. elliptica, Brongt., and Sig. notata, Steinhauer, sp., are 

 only forms of S. mamillaris, or individual species, must therefore in the meantime 

 remain open. 



Horizon: — In Blue Bind, at a depth of 533 yards. 



Sigillaria, sp. 



Horizon : — At a depth of 533 yards. 



Cyperites bicarinata, L. and H. 



Horizon: — At a depth of 533 yards. 



Stigmaria, Brongt. 



Stigmaria ficoides, Stemb., sp. 

 Horizon: — At a depth of 533 yards. 



* Brongt., Hist. d. ve'gd. foss., p. 447, pi. clii. figs. 1, 2 ; pi. clxiii. fig. 4. 



t Steinhauer, Trans. Amer. Phil. Soc, 1818, p. 294, pi. vii. fig. 3 (Phytolithus notatus). 



X Brongt., Hist. d. ve'ge't. foss., p. 449, pi. cliii. fig. 1. 



§ Boulay., Le terrain houiller du Nord de la France et ses vtfge'taux fossiles, p. 43, Lille, 1876. 



