74 FLORA OF LOWER COAL MEASURES OF MISSOURI. 



have been described as Alethopteris or referred thereto. On the whole, this 

 gi'onp of species constitutes a division or section quite distinct from the 

 other sections of the genus Pecopteris, which shoukl either be transferred to 

 some other genus, if that is found practicable, or separated as the basis of a 

 new genus. By most recent authors they are referred to the genus Sphenop- 

 teris, and it would indeed seem that they are most closely related to and 

 congenenc with Sphenopteris Essinghii Andra, which binds them to Sphenop- 

 teris mmquilateralis Lx. Sphenopteris Sternbergii (Ett.) Weiss was placed in 

 the fertile genus Saccopteris by Stur, and Saccopteris (= Grand 'Eurya 

 Zeiller) is regarded^ as identical with Baily's Corynepteris? Thus most of 

 these species like Sphenopteris Ussinghii have found places in Corynepteris or 

 its synonpns. The close resemblance of the fertile pinnae from Missouri, 

 obscure sjiecimens of which are found in PI. XXIII, Fig. 5, to the specimens 

 figured bv Zeiller^ as Sphenopteris (^Corynepteris^ coralloides Gutb., is at once 

 apparent, even the narrow dichotomous filaments extending out from the 

 slightly reduced limb being similar in both species. This circumstance, 

 together with the demonstration by Zeiller* of the same type of fruit in 

 Sphenopteris JEssinghii, leaves little room for doubt that the fructification of 

 our American plant is probably of the CorynepAeris ix^e. Our specin^iens, 

 though badlv crushed, seem to confirm this view; but while the sporangia 

 are shagreened and would seem to be grouped in a manner similar to Cory- 

 nepteris, I have not yet been able to distinguish the zone of the thickened 

 cells found in the sporangia of that genus. 



Localities. — Frequent at Pitcher's bank, U. S. Nat. Mus., 5551, 5610, 

 5611, 5613, 5721; Owen's coal bank, U. S. Nat. Mus., 5609, 5613; Deep- 

 water, U. S. Nat. Mus., 5552, 5689; Hobbs's coal bank, U. S. Nat. Mus., 

 5690; Gilkerson's Ford. 



PECOPTERIDE.E. 

 PECOPTERIS Brouguiart, 1822. 



1822. Filicites sec. Pecopteris Brongniart, Mem. mus. liist. nat., voL viii, p. 233. 

 1826. Pecopteris Sternberg, Versuch, vol. i, tent., p. xvii (pars). 

 1828. Pecopteris Brongniart, Prodrome, p. 54. 



' Kidstou, Trans. Roy. Soc. Edinb., vol. xxsiii, 1887, p. 381. 

 - Explau. sheet 142, maps, Geol. Surv. Ireland, 1860, p. 16. 

 ■'1"1. foss. hoiiill. A'alenciennes, Atlas, pi. x, tigs. 1, 2. 

 ■•Op. cit., text,"p. 12.5. 



