FERNS— SPHENOPTBRTDE.E—SPHENOPTERIS. 41 



SpHENOPTEBIS (HYMENOTHECA) BEOADHEADI II. SI). 



PL XIII, Figs. 1,2. 



1897. 8j)henopt€ris sp., D. White, Bull. Geol. Soc. Amer., vol. viii, p. 296. 



Fertile frond tripiunate; primary pinnae linear-lanceolate, acute; pri- 

 mary rachis broad, flat above, irregularly finely striate; secondary pinnse 

 open, somewhat oblique or nearly at a right angle to the primary rachis, 

 subopposite or alternate, rather distant, linear, tapering fr-om the base to a 

 rather acute point; secondary rachis indistinctly striate, more or less rigid; 

 ultimate divisions or pinnules subopposite, oblique, strongly decurrent, 

 either simple, cuneate, rounded above and arching inward, or forking once 

 or more pinnately and divergently, always preserving the cuneate form 

 of lobes with rounded ends, while passing into the pinnae, wliich are at first 

 1 cm. or more in length, with 5 to 7 pinnules, then elongating with divided 

 basal piimules; lamina moderately thin, slightly rugose. Nervation thin, 

 the primar}- nerve forking pinnately at the base of each lobe or pinnule, 

 each of which is traversed by a branch. Fructification consisting of oval 

 or round-oval sporangia placed one upon and nearly covering the end of 

 each lobe or pinnule. 



Although the sterile form of this species is not definitely known to me, 

 the fertile form possesses so much that is of interest and new to our flora 

 that I describe it here without waiting for the correlation of the fertile and 

 sterile portions of the plant. Owing to the coarsely arenaceous character 

 of the matrix, the detail of the fruiting is not so clear as is desirable, the 

 general appearance of the compressed sporangia being that of granular, 

 carbonaceous matter. In this state it resembles somewhat the Discopteris 

 Schumanni of Stur's Carbon-Flora.^ But at several points the sporangia 

 show a slightly raised ridge or keel parallel to the longer axis, apparently 

 like that of the Ilymenopliyllites figured by Schimper,^ and still more 

 strongly resembling the Hymenotheca DatJiei of Potonie.^ In fact, the rela- 

 tionship of our fern with that described by Potonie is so evident from the 

 details, so far as they are visible, as well as from the form and habit of the 

 frond, that little room for doubt is left as to its actual generic identity. 



'Page 149, pi. Ivi, figs. 2, 3. -Traite, vol. i, p. 415, pi. xxviii, figs. 4-8. 



' Jahrb. K. Pr. geol. Landesanst. u. Bergakad., 1889 (1892), p. 20, pi. ii, figs, la, 16, Ic. 



