GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



257 



each separate leaf being seven-eighths of an inch long 

 by two-eighths broad— approximate, though separate, 

 throughout their length: those of the P. cistii being 

 occasionally united at base. The length of the leaves in 

 the latter species is not quite double their breadth, whilst 

 these organs are in length three times their breadth in 

 the "obsoleta;" but what would appear to distinguish 

 the P. obsoleta from all other species of this genus, is 

 the interruption of the basil attachment of the upper half 

 of the leaf, which appears unconnected with the stem in 

 many instances. All vestige of nervures is totally ob- 

 literated from the leaves of the obsoleta/' which, in 

 other respects, is a bold and well relieved specimen. 

 Vide pi. 14, fig. 2. 



Pecopteris Milleri. 



P. pinnulis obliquis, rectis, linearibus elongatis, vix 

 distinctis; nervulis simplicibus, valde obliquis. 



Geological position and locality the same as the pre- 

 ceding species. This most perfect specimen, which ap- 

 pears as if sculptured on the accompanying rock, consists 

 of a fragment of a stem 3| inches in length, displaying 

 alternate curvatures, with four branches 2 inches long on 

 either side, alternating with each other, each bearing 

 from fifteen to twenty leaves half an inch long and two- 

 eighths of an inch broad, separate from each other, obo- 

 vate, linearly curved, and at their distal extremity point- 

 ed ; with numerous simple oblique nervures. 



This species is allied to the Pecopteris Beaumontii of 

 Brongniart— Hist, des Veg. Foss. pi. 112— from the coal 

 measures of the Alpine Lias, but is distinguishable by 

 the simplicity of the nervures (those of the latter being 

 dichotomous), also by the form of the leaf. 



We have dedicated this species to our valuable asso- 

 ciate Mr Edward Miller, author of the geological me- 

 moir alluded to above, and to whom the Society has been 

 I.— 2 H 



