78 PP. REPORT OF PROGRESS. FONTAINE & WHITE. 



ward the lower part of the plant, all longer and larger than 

 the normal ones, and possessing rounded lobes; pinnules of 

 the middle portion (normal pinnules), small, oblong, ob- 

 tusely rounded at the end ; pinnules near the summit of the 

 same shape, but very minute ; mid-nerve, well-defined, but 

 slender ; lateral nerves, all very delicate, those in the lower 

 lobed pinnules twice forked, those in the central portion of 

 the plant once forked a short distance above their insertion ; 

 fructification, consisting of two rows of rounded or slightly 

 elliptical sori, raised like mamillse, placed on each side of the 

 mid-nerve, and covering the greater portion of the surface 

 of the pinnule.) 



The texture of the plant seems to have been pretty dense, 

 and the compression of the slender nerves in this thick 

 substance causes them usually to have a peculiar entangled 

 appearance. The sori are so closely placed, that they often 

 appear to be imbricated. Fig. 1 represents the pinnules 

 from the lower part of the plant, where they appear to tend 

 to pass into pinnae. The general facies of the plant resem- 

 bles the more delicately cut forms of P. arborescens, but 

 the points of difference are well marked and constant. 



Habitat. — Roof-shales of the Waynesburg Coal, Cass- 

 ville, W. Va. 



Pecopteris Merianiopteroides. Sp. nov., PL XXIX, Figs. 

 1-2. 



(Frond, tripinnate; primary pinnae, triangular in outline; 

 secondary pinnse, linear-lanceolate, going off at almost a 

 right angle ; pinnules, obtusely ovate, united at the base, 

 and inclined slightly forward ; mid-nerve well defined, lat- 

 eral nerves numerous, once forking, and departing under 

 an acute angle, those from the lower side of the pinnule 

 passing off from the attachment of the pinnule to the 

 rachis.) 



The general facies of the plant, together with its nerv- 

 ation, very much resemble the form described by Heer in 

 his "Trias u. Jura. Pflanzen," on which he founded the new 

 genus of Merianiopteris, hence the name we have given it. 



