J. W. Dawson — Erian Flora of the United States. 341 



of pinnae for the length of one or more inches. (3.) The stems 



(4.) In a few instances the fronds were observed to divide 

 'lieliotumously toward the top; but this is rare. (5.) There 

 are no indications of cells on the pinnules; but, on the other 

 hand, there is no appearance of fructification unless the minute 

 granules which roughen some of the stems are of this nature. 

 (6.) The stems seem to have been lax and flexuous, and in 

 some instances they seem to have grown on the petioles of 

 ferns preserved with them in the same beds. (7.) The fre- 

 quency of the attachment of small brachiopods to the speci- 

 mens of Ptllophijton would seem to indicate that the plant stood 

 erect in the water. (8.) Some of the specimens show so much 

 carbonaceous matter as to indicate that the pinnules were of 

 considerable consistency. All those id anietrr » are those rather 

 of an aquatic plant than an animal organism or a laud plant. 



The specimens communicated by Professor Lesquereux and 



Mr. loroe are from the Lower Carboniferous, and evidently 



represent a different species with similar slender pitted stems, 



tially denuded of pinnules below; but the pinnules 



"e much broader and more distant. They are attached by 



though they ma \ possibh hav< beenspiralh arranged. On 



the same slabs are rounded sporangia or macrospores like those 



"h-on, but there is no evidence that these belonged 



t" Trorho^hyUnm. fin the stem- of this plant, however, there 



may be merely imperfectly developed pinnules. Still the 

 wat similar small granules appear on the stems of the Devo 

 species, favors tie id< t at thev i in e « M-aiis of i'ructirlca 



and no.babiy ^x\^\ to float the 



' manv of the peculiarities in the ; 



• the Devonian Ptl"> 



Ca°rn P °! 

 ^arbonif 



gashed by their linear leaves serving as tloats am 

 Pinnately on slender stems. The only species yet fo 



