40 FLORA OF LOWER COAL MEASURES OF MISSOURL 



Tliis somewhat unique species in our American Coal Measures flora is 

 specially characterized by the extremely small size of its parts and its 

 minute, rounded pinnules, which are round-crenulate or roundish, crenu- 

 late-lobate in almost the earliest stage, the lobes being marked as mere 

 scallops or deep crenulations and cohering until a period of deeper dissec- 

 tion, to form simple round or oval pinnules, whereupon the latter beo-in at 

 once to show 2 to 5 or 7 crenulations, repeating the form of dense coherent 

 clusters. 



When first examining the specimens the observer is at once impressed 

 with the similarity in their form, habit, and grosser details to Sphenopteris 

 {Conjnepteris) coralloides Grutb.,^ the species to which S. Wardiana is per- 

 haps most nearly related ; but a study with the lens of the minute divi- 

 sions shows differences in form, substance, and nervation as great as those 

 between many of the larger species in the group. The pinnules or lobes 

 in the plant from Missouri, Fig. 2, PL XI, are much more ovate, not so 

 truncate, the crenulations fewer and occurring on the sides of the rounded 

 or ovate pinnules, neither so dentate at the top nor so constricted at the 

 base as in the plant figured by Gutbier. In S. Wardiana the texture of 

 the pinnule is leathery, the principal nerves of no unusual thickness, and 

 the nervils, which are less fasciculate, are rather thin and difficult to dis- 

 cover. Sphenopteris canadensis Pn., from the Carboniferous of New Bruns- 

 wick, is larger, more lax, the divisions naore elongated and less crenulate, 

 wlaile the texture is membranaceous. In its general aspect Sphenopteris 

 Wardiana suggests a microphotograph of the smaller pinnules of S. Lacoei 

 or 8. mixta. It belongs perhaps to that group of Sphenopterids represented 

 by Sphenopteris Hceninghausii Brongn. 



This interesting species is named m honor of Prof Lester F. Ward, 

 whose thoughtfiil and very thorough methods in the field of con-elative 

 and philosophical paleobotany have revolutionized the treatment of fossil 

 plants in this country, while accomplishing a distinct benefit to the science 

 in its broader and more comprehensive aspects. 



Localities.— Owens's coal bank, U. S. Nat. Mus., 5617; Pitcher's mine, 

 U. S. Nat. Mus., 5615. 



' See in particular the fragments and details given in Gutbier, Abdriicke, p. 40, pi. t, ligs. 8, 8a; 

 or Zeiller, Fl. foss. houill. Valenciennes, p. 117, pi. x, figs. 4, 4a, 5, 5a. 



