1862.] DAWSON — DETONIAN PLANTS. 315 



30. PSILOPHYTON PEIXCEPS, DaWSOll. 



Quart. JoiuTi. Geol. Soc. yoI. xv. p. 479, figs. 1 a to 1 i. 



This remarkable plant, so characteristic of the whole Devonian 

 system at Gaspe, filling many beds with its rhizomes, in the manner 

 of the Stlgmaria of the Coal-measnres, and preserved in such 

 abundance and perfection that it is much better known to us in its 

 form, structure, and habit of growth than any other plant of the 

 period, proves, as might have been anticipated, to have had a wide 

 distribution in space as well as in time. Fragments of its stems are 

 distinguishable in the sandstones of Perry, and numerous fine speci- 

 mens occiu' among the jplants from New York State committed to 

 me by Prof. Hall. It occiu's in the Hamilton group at Schoharie, 

 New York, and at Akron, Ohio, in the Chemung group at Cascade 

 Falls, and in the Catskill group at Jefferson. Most of the specimens 

 are stems, which show the habit of growth very perfectly. They 

 confirm my inference from the structure of the Gaspe specimens that 

 the plant was woody and rigid, as they often do not lie in one plane, 

 but extend upward and downward in the manner of firm branches 

 buried in sand. Most of the New York specimens seem to have been 

 drifted; but groups of rhizomes, possibly in situ, occur in argillaceous 

 sandstone from Fullenham, Schoharie, and in similar beds at Caze- 

 novia and Cascade Falls. These are the only instances presented by 

 Prof. Hall's collections of root-beds resembling those of Gaspe. In 

 New York only the Upper and Middle Devonian have as yet afforded 

 land-plants ; but in Gaspe Psilophyton ]orinceps occurs in the Lower 

 Devonian, and fragments which may have belonged to it occur in 

 the Upper Silurian. 



31. PsiLOPHTTON ELEGANs, sp. uov. PI. XI Y. figs. 29, 30; and 



PI. XY. fig. 42. 



Stems slender, produced in tufts from tJiin rhizomes, hifurcatlng and 

 curving at their summits. Surface smoot7i,tuit7i very delicate ivrinlcles. 

 Fructification in groups of small, hroadly oval scales, home on the 

 main stem helow the points of bifurcation. ': 



I distinguish this species from Psilophyton princeps by its smaller 

 size, its smoother surface, its growth in tufts, and the different form 

 of its organs of reproduction. Still it must be admitted that im- 

 perfect specimens coidd not readily be distinguished from branchlets 

 of P. princepjs. It was found by Mr. Matthew in the shales near 

 Carlton. 



32. PSILOPHTTOX? GLABEUM, Sp. nOV. 



Smooth, flattened, bifurcating stems, two lines in width, with a slender 

 woody axis. 



These are objects of doubtfid natui-e. They must have been stems 

 or roots, bifurcating in the manner of Psilophyton, but having a 

 very slender woody axis. They may have been either roots of some 

 plant, or stems of a smooth and comparatively succulent species of 

 Psilophyton, 



