17 



which, in the former, is about a third greater than in 

 the latter. 



Locality, in coal formation, — Pennsylvania. 



SIGILLARIA RUGOSA, BRONG. 

 PI. II, fig 1. 



Brong. Ilist. veget. foss. I, 2^. 446, jjI. 144, ^g. 2; Prodr. p. 64. 

 linger , Gen. et Sjiec. jfJ. 249. 



Trunk longitudinally and prominently furrowed ; flu- 

 tings parallel and commensurate. 



Denuded of its cortical integument our specimen ex- 

 hibits the following characteristics : — surface slightly 

 punctate; cicatrices discoid-ovate, situate, longitudinally, 

 remote from each other, — laterally, in the middle of 

 the fluting and leaving on either side a margin equal to 

 their own breadth; vascular bundles denoted by two 

 opposite, nearly crescent shaped markings, — between 

 which is a third dot-like impression; longitudinally in- 

 tervening the scars is a prominent marking, gradually 

 expanding in breadth as, from the middle, it approaches 

 the scars. 



Invested with its bark-like exterior: — surface lon- 

 gitudinally, delicately striate; position of cicatrice de- 

 noted by a distinct knot-like marking; longitudinal de- 

 velopement between the scars not appearing. 



Between Brongniart's figures of this species and our 

 fossil impression , there exist two slight disparities : — 

 firstly, in respect to the form of the cicatrice, which, 

 according to Brongniart, assumes less of a discoid-ovate 

 contour than is observable in the present instance ; and, 

 secondly , in respect to the form of the so-called rugos- 

 ity, which Brongniart has represented as nearly uni- 



2 



