26 FLORA OF LOWER COAL MEASURES OF MISSOURL 



furrow or g-utter; pinnules of the upper secondary pinnae broad, more or 

 less deeply dissected into 3, sometimes 4, broad, rounded or truncate- 

 rounded, or obovate lobes, the lowest pair of the pinnules of the pinnae 

 subpalmately divided into 4 to 6 lobes, one or more of the divisions 

 sometimes elongated, those pinnules toward the top of the pinnae becoming 

 less distinctly lobed and approaching the proportions of those borne on the 

 tertiary pinnae; primary nerves originating at a narrow angle and curving 

 outward, dichotomizing, the secondary nerves forking and curving, indistinct, 

 to the border; fructification unknown. 



The excellent suite of specimens from Missouri representing SpJienopteris 

 dbtusiloba Brongn. has already been described somewhat fuUy.^ The lines 

 of the differentiation of this species from Sphenopteris trifoliolata Artis are 

 still uncertain, although it is quite well recognized that more than one species 

 is included under the two names. 



The examination of the originals of the Pseudopecopteris irregularis 

 (Sternb.) Lx. figured^ from the same locality as some of the specimens 

 before me, and a comparison of these with material from the same place, 

 published later by Lesquereux^ as Pseudopecopteris obtusiloha (Brongn.), 

 show that, so far as the specimens from Missouri are concerned, the only 

 difference between the few examples identified by that author is that of size. 

 The more complete representation shows every gradation from the small 

 fragments such as that figured as Ps. irregularis in the Coal Flora, or Fig. 1, 

 PI. VII, and the average proportions, there being no specific distinction 

 between them. The specimens illustrated on PI. VII, Figs. 2, 3, and 

 PL VIII, show well the general aspect of fragments from the various parts 

 of the primarjr pinnae. Many of the trilobate pinnules of the form seen in 

 the upper part of PI. VII, Fig. 3, enlarged in PL IX, Fig. 5, somewhat 

 resemble the Pseudopecopteris anceps Lx.* 



The collection of specimens from other American localities identified 

 as Pseudopecopteris obtusiloha seems to show several phases of this species, 

 one or more of which may deserve at least varietal distinction, while it is 

 possible that the true Sphenopteris trifoliolata of Artis is also present. 



' Bull. U. S. Geol. Surv., No. 98, 1893, p. 53. 

 - Lesquereux, Coal Flora, vol. i, p. 212, pi. lit, figs. 1, 2. 

 ■■'Op. clt., vol. iii, p.753. 



■'Pseudopecopteris sqtiamoaa (Lx.) has priority over Ps. anceps, which is identified by Zeiller and 

 Kidstou as Splienopteiis ncuropteroidea (Boulay) Zeill. 



