120 FLOKA OF LOWEK COAL MEASURES OF MISSOUKI. 



somewhat contracted at the base; secoudary pinniB open, alternate, suboijposite or 

 opposite, oblique above, somewhat reflexed below, simple except near the base of the 

 largest x^rimary pinnffi, straight or slightly tiexuous, sometimes slightly decurrent, 3-6 

 cm. distant on the same side, more or less overlapping, linear-lanceolate, or oblong-lance- 

 olate, rather acute, averaging about 2 cm. in length and 4.5-9 cm. in width where simply 

 pinnate, sometimes slightly contracted at the base and tapering to a rather oblong- 

 lanceolate obtusely acute terminal pinnule; secondary rachis, like the midribs of the 

 pinnules, distinctly finely striate; pinnules normally open, nearly at right angles to 

 the rachis, more or less distant, rarely touching, linear-lanceolate, generally broadest 

 in the middle, obtusely acute at the apex, decurrent along the rachis with an acute 

 sinus, and always distinctly united by a decurrent lamina of considerable width, the 

 surface of the pinnule somewhat convex, the borders frequently folded beneath; mid- 

 rib large, usually slightly decurrent, often straight, deeply depressed, finely striate, 

 and passing nearly to the extreme apex; uervils quite coarse, salient, sometimes dis- 

 tinctly striate under the lens, springing at a generally wide angle from a line in the 

 center of the groove on the dorsal surface of the pinnule and curving rapidly, often 

 passing nearly straight from the midrib and extending, almost directly i^arallel and 

 rather close, to the border, which they meet at a right angle, forking generally once 

 close to the point of origin, the upper branch usually forking again, though often 

 remaining simple, and numbering 28 to 42 per centimeter at the margin. 



Localities. — Normal form at Owen's coal bank, M-wa. Reg. 3596; Henry 

 Comity, Missom-i, U. S. Nat. Mus., 5486. The variety is from Owen's coal 

 bank, kus. Reg. 3594, 5473, 54S7. 



GALLIPTERIDIUM Weiss, 1870. 



Zeitschr. d. deutsch. geol. Gesell., vol. xxii, pp. 858, 876; Lesquereux, Goal Flora, 



vol. i, 1880, p. 164. 



GALLIPTERIDIUM MEMBRANACEUM Lx. 



PI. XXXVIII, Figs. 1-5. 



1879. CallipferidiKm meinbranaceum Lesquereux, Goal Flora, Atlas, p. 6, pi. xxvii, figs. 

 5, 5«, (uon 6, 8); text, vol. i (1880), p. 172 (pars). 



Frond tripinnate, rather lax, Alethopteroid ; secondary pinna^ linear- 

 lanceolate or oval, acute or acuminate, alternate, open, reflexed below, a 

 little distant; secondarj^ rachis strong, broad, rather coarsely striate, the 

 rachises of the tertiary pinnae originating from a little within the border on 

 the ventral surface ; tertiary or ultimate pinnte alternate, open, at a right 

 angle to the rachis, or reflexed below, a little distant, not decurrent, linear 

 or linear-lanceolate, hardly constricted at the base, the sides parallel in the 

 middle and converging near the pinnatifid or crenulate apex, which is acute 



