98 FLOKA OF LOWER COAL MEASURES OF MISSOURL 



Bkittsia problematica n. sp. 

 PI. XLVII, Figs. 1-5; PI. XL\in, Figs. 1-3. 



Primary piniife small, oval or round, consisting of a short, broad, lax, 

 flattened axis, from which radiate, distichously, lingulate crenulated thalloid 

 (?) branches or secondary piunse, each of which is provided with two 

 rows, one on each side of the rachis, of alternate, denticulate, imbricated 

 scales or pinnules ; main axis rather coarsely and irregularly striate, as if to 

 correspond to the course of lax vascular bundles, 4 to 8 cm. long or longer, 

 2 to 5 mm. or more in width at the base, expanded and relaxed to a much 

 greater width in the middle, dissolving somewhat rapidly at the top, and 

 bordered on either side by a rather thick lamina which extends along the 

 lateral pinnte, joining them near their bases; lateral pinnae alternate, close, 

 iLsually somewhat overlapping, the lowest much reflexed, the middle ones 

 at a right angle to the axis, the upper ones becoming more oblique, so 

 as to impart a somewhat radial effect, lingulate, 1 to 5 cm. long, 7 to 

 10 mm. broad, slightly narrower at the base, often broadest in the upper 

 part, obtusely rounded at the apex, each piima composed of a broad, sinuate, 

 bandlike, lax rachis at a right angle to, or but slightly decurrent to, the 

 principal axis, 1.5 to 3 mm. wide, giving- ofiP short, obliqiie branches 

 alternately and regularly at intervals of from 2.5 to 5 mm. on the same 

 side, which pass through and out of the rachial lamina or border close to 

 the rachis to enter the pinnules; border of the lateral rachises continuous 

 with that of the main axis, not very thick, minutely coriaceous, 2 to 5 

 mm. wide on either side, the margin obscure, apparently broken irregu- 

 larly or crenulate-erose, depressed in shallow pits, or gathered slightly at 

 the vascular base of each pinnule; pinnules alternate, originating one from 

 each of the vascular pits in the rachial lamina, asymmetric, ovate, or obovate- 

 cimeate, 8 to 12 mm. long, 5 to 8 mm. wide, apparently narrow at the point 

 of attachment, arching outward at first, then broadening and spreading over 

 the rachial lamina, inclined upward, imbricating, the margin incised in sharp 

 or rather broad, not very long teeth; leaf substance of 2jinnules not very 

 thick; nervation coarse, broad, flabellate from the base of the pinnule in a 

 broad fascicle, the wide strands forking two to four times at a narrow angle 

 and arching somewhat in their passage to the extremities of the teeth. 



A general idea of the form and habit of this somewhat problematic 



