DESCRIPTION OF SPECIES. PP. 75 



Habitat. — Roof shales of the Waynesburg Coal, Cassville, 

 West Virginia. 



Pecopteris Schimperiana. Sp. nov. PI. XXIV, Figs. 1-5. 



(Frond, tripinnate ; primary racliis stout, and rather 

 rough • secondary pinnse alternate, linear-lanceolate, taper- 

 pointed, going off at nearly a right angle ; pinnules, short- 

 ovate, or triangular in outline, alternate, decurrent, and 

 united near the base in the lower pinnae, and more and 

 more united as we pass towards the summit of the frond, 

 or of the pinnae ; texture, thick and leathery ; mid-nerve, 

 strong and flexuous, extending to the apex ; lateral nerves 

 stout, and forking dichotoraously in a straggling manner. 

 The branches all being deflexed, so as to meet the margin 

 of the pinnules almost under a right angle.) 



This plant is one of the most distinctly characterized ones 

 that we have met with in the Upper Carboniferous tlora. 

 It shows two forms, which present a somewhat different 

 facies, viz : that given in Figs. 2, 1, 3 and 5, and the one 

 depicted in Fig. 4. The first form has more acute pinnules, 

 which, in small pinnae near the summit of the frond, become 

 quite pointed. The form given in Fig. 4, has obtuse, falcate 

 pinnules. This if seen alone might be taken as a dis- 

 tinct species, or at least variety ; but the peculiar nerva- 

 tion of the form first described is possessed by this also, 

 and the presence of intermediate links forbid the separation 

 of the two. 



This species in several features closely resembles Brong- 

 niart's P. Sulziana, from the base of the Trias, as figured 

 in the Hist. d. Veg. Foss., p. 225, Tab. CV, Fig. 4. It is 

 possible that the change of facies seen in Fig. 4 is caused 

 by the fact that this portion of the plant comes from the 

 top of the frond. Fig. 2 shows a fragment from the lower 

 part of the plant, where the triangular pinnules begin to 

 show a tendency to become lobed, as if about to form new 

 divisions. It is probable that still lower these may pass 

 into pinnatifid pinnae. 



Habitat. — Roof shales of the Waynesburg Coal, West 

 Union, AVest Virginia. 



