FOSSIL PLANTS. 453 



small scars of rootlets, generally placed without symmetrical 

 order, and without a central vascular point. 



The affinity of this genus with the former appears at first very close ; but we 

 have here species, evidently roots, some of them rhizomas of ferns, marked by 

 irregularly placed scars, which cannot be united to a genus which, even if it 

 should represent a kind of roots, is far different in its essential characters, viz : 

 the regularity of position and the form of the scars. The name of Rhizolitcs, 

 P. Braun., a genus enumerated but not described by Unger, might be, there- 

 fore, appropriate if, per contra, the species had not a near relation to those of 

 the former genus, by the form of the cicatrices and of the leaves. 



All these species appear to have been of a soft substance, and without excep- 

 tion, have been found preserved in nodules. 



STIGMARIOIDES TRUNCATUS, Sp. nov. 



PI. xxix, fig. 4. 



A cylindrical root, about one inch in diameter, with a smooth 

 surface, marked with small round cicatrices, without order of 

 position. These cicatrices vary much in size, and are evidently 

 scars, left at the base of short, horizontal, flat rootlets, scarce- 

 ly one line broad, without mark of a vascular line. The vas- 

 cular point is also absent in the middle of the scars, or marked 

 by a mere cavity. 



This species resembles the one published in vol. ii of this Report, p. 448, 

 pi. xxxix, fig. 9, under the name of Stiymaria Evenii, which has the surface 

 undulately ribbed and broader scars, and is also referable to this new genus. 



Found at Mazon creek, in concretions of argillaceous iron ore. 



STIGMARIOIDES TUBEROSUS, Sp. nov. 



PI. xxix, fig. 5. 



I do not know any vegetable organ to which these peculiar 

 remains could be compared. The specimen figured represents 

 a nearly round or square oval tubercle, with a convex sur- 

 face covered with small round points irregularly placed, re_ 

 sembling scars of hairs or scales. In its upper part it is 



