FEENS— SPHENOPTERIDE.E— SPHENOPTERIS. 53 



Sphenoptebis Brittsii Lx. 

 PI. XV, Fig. 1; PI. XVI; PI. XVII; PI. XVIII, Figs. 1, 2; PI. XIX, Fig. 3. 



1879. Sphenopteris Brittsii Lesquereux, Coal Flora, Atlas, p. 10, pi. Iv, tigs. 2, 2b; text, 

 vol. i (1880), p. 277 (vol. iii, 1884, p. 764, pi. cii, figs. 3, 4, 4«,?). 



1888. Sphenopteris Brittsii Lesquereux, 13th Rept. Geol. Surv. ludiaua, p. 21G, pi. xv, 

 fig. 3. 



1890. Splienopteris Brittsii Lx., Lesley, Diet. Foss. Penusylvaina, vol. iii, p. 983, text flg. 



1893. Ovopteris Brittsii (Lx.) Potonie, Fl. Rothl. ThiiriLgeu, p. 44. 



Fronds large, tri(poly-!)pmnate; racliis of the various orders well devel- 

 oped, flexuous, sometimes slightly subgeuiculate, low-rounded beneath, 

 broadly and shallowly canaliculate on the upper surface, faintly striate, 

 rough, provided with short lax scales or spinous scales; primary (?) pinnae 

 alternate, very open, often at a right angle to the rachis, or reflexed, stand- 

 ing close, usually overlapping, flexuous or sinuate, lanceolate or linear-lanceo- 

 late, acute, more or less lax, contracted toward the base and presenting a 

 rather rough surface and ragged margin on account of the uneven lamina 

 and the slightly repand and sharp-toothed border; pinna? of the next order 

 alternate, open, somewhat arched backward below, flexuous, close, frequently 

 o^-erlapping, usually curving upward and parallel, but often at a right angle 

 to the rachis, and sinuate, linear, tapering from near the base to the slightly 

 obtuse apex, sometimes very slender, flexuous, and reduced toward the base ; 

 ultimate pinnae alternate, generally rather close, less often touching or 

 slightly overlapping, very open, nearly at a right angle to the rachis in the 

 lower part of the pinna, OA'ate-triangular, obtusel}" pointed, wider on the 

 upper side at the base, usually curving upward somewhat, slightly flexuous, 

 with depressed, well-marked punctate-rugose rachis, and joined b}' a narrow 

 decurrent lamina; pinnules alternate, close, compact, usually slightl}^ over- 

 lapping, set obliquely by a broad attachment, ovate or ovate-triangular, 

 arching upward, unsymmetrical, much wider on the upper side at the base, 

 the lower side being slightly reduced, broadly ovate, the u^^per part pin- 

 nately cut in narrow, very short, obtuse, strongly upward-pointed teeth 

 when young, becoming more triangular and pinnately lobed by very shallow 

 narrow sinuses in five or more upward-inclined divisions when larger, the 

 lobes broad, truncate-rounded, bi- or tri- to quinqviedentate, increasing to 



