FERNS— SPHENOPTERIDE.E—OLIGOCAEP1A. (37 



finely liueate, dull, flexuous, those of the last order being very thin and 

 sinuate; secondary (?) pinnae alternate, originating at an open angle to the 

 primary rachis and curving outward, close, or slightly overlapping, flexu- 

 ous, lanceolate or linear-lanceolate, contracted toward the base, and taper- 

 ing above the middle to the acute apex; ultimate pinnae open, often at a 

 right angle to the rachis, alternate, rather distant, flexuous, linear-triangular, 

 tapering from near the base to the slender, narrow apex ; pinnules alternate, 

 ovate, becoming crenulate in passing to the pinnatifid stage, distant, open, 

 at a right angle to the rachis in the lower portion of the longer pinnae, 

 obtusely rounded at the summit, with rounded margin on the lower side, 

 the upper side straighter, giving the pinnule an upward turn, attached by 

 the whole or nearly the whole base until becoming pinnatifid, and sepa- 

 rated nearly to the rachis by a broad sinus, which is usually round or 

 squarish, and sometimes slightly decurrent at the lower angle; lamina 

 dull, not very thick; nervation rather coarse, often obscure on the upper 

 surface ; primary nerve decurrent, rather strong, striated, arching with the 

 pinnule, flexuous, and forking pinnately at a rather open angle, the lower 

 nervils forking again or even a second time as the pinnule becomes pin- 

 natifid; fructification within the margin, in 1 to 7 round depressions, in 

 each of which appears one or more sporangia, apparentl}^ of the type of 

 Oligocarpia, although the characters are obscure. 



The sterile examples incompletely shown in Figs. 1, 2, PI. XX, and 

 Fig. 3, PI. XXI, from Owen's coal bank, appear to form a fairly distinct spe- 

 cies, closely related to"0. alabamensis Lx. and 0. Gutbieri Groepp. The o-en- 

 eral aspect of the large pinnte illustrated in Fig. 1, PL XX, will at once be 

 noted as quite similar to the figure of 0. alabamensis^ given by Lesquereux. 

 But the latter has the rachis opposite or subopposite, while the pinnules are 

 close and much more open, instead of being distant and curved upward, as 

 in the species from Owen's. Furthermore, the primary nerves in the Ala- 

 bama type are much less decurrent. The fertile pinnae in the large speci- 

 men bear also some resemblance to Oligocarpia Brongniartii Stur.- 



My reference of the plant to the genus Oligocarpia is based on the strik- 

 ingly similar conformation of the vegetative part and that of other species 



' Coal Flora, vol. i, p. 266, pi. slvii, figs. 1 a-ft. 



= Farno fl. Carl)on-Flora, p. 131, pi. Ivii, figs. 2, 3. See also Zeiller, Fl. loss, bassin. houill. Valen- 

 ciennes, p. 07, pi. xi, figs, 3, 3«-c, 4, 5, oa-u. 



