40 PP. KEPOKT OF PROGRESS. FONTAINE & WHITE. 



PERNS. 



Sphenopteris, Brongt. 



The Sphenopterids are by no means so fully represented 

 in the flora of the Upper Carboniferous, ' either in the num- 

 ber of species, or individuals, as are the Pecopterids. The 

 specimens of this genus are found sparingly, and the indi- 

 viduals are never, as is the case with many Pecopterids, 

 abundant enough to form the preponderating element in the 

 flora of any locality. The facies has changed greatly from 

 that shown in these ferns at lower horizons. We And no 

 species retaining the composite type shown in the SjDhenop- 

 terids of the Conglomerate and Lower Coal Groups, as ex- 

 emplified in S. macilenta, S. latifolia, &c. The facies of 

 the plants of the upper beds seems rather to belong to 

 horizons higher even than the Carboniferous, and reaching 

 into the Rhaetic, and Oolite. It is a peculiar fact that we 

 find, as yet, no well characterized Sphenopterid above the 

 horizon of the Waynesburg Coal, although in many locali- 

 ties the shale is of a nature fitted to preserve the most deli- 

 cate plants. 



8phenopteris acrocarpa^ Sp. no v. PL III, Figs. 1-3 ; 

 PI. IV, Figs. 1-5. 



(Frond, tripinnate ; primary pinnse, triangular, or lanceo- 

 late in outline, curving upward from the rachis at an acute 

 angle ; secondary pinna3, sub-alternate, long, narrow, and 

 somewhat pointed, the lowest one on the upper side being 

 the longest and most complex in division, and extending 

 up parallel with the principal racliis ; pinnules of the lower 

 and middle portions, lanceolate in outline, acute, and la- 

 ciniate on the margin, the incisions making a very acute 

 angle with the mid-rib of the pinnule, contracted at the 

 base, and attached under a very acute angle to a narrowly 

 winged rachis ; laciniae of the lower pinnules of the frond, 

 and pinnae, notched and toothed ; of the middle portion, 

 passing into teeth; and in the upper pinnge, being lost, caus- 

 ing the incised pinnules, to pass into small ovate ones, with 

 entire margins ; mid- nerve of the pinnule, somewhat flexu- 



