88 SIXTEENTH REPORT ON THE CABINET OF NAT. HISTORY. 



I am indebted to Dr. J. S. Newberry for the cast, specimen figure 2, 

 which was collected in the vicinity of Cuyahoga falls, from whence I have 

 many years since (1841) obtained numerous fragments of the same. 



The more perfect specimen which I have referred to this species, was col- 

 lected by Dr. C A. White, at Richfield, Ohio, in rocks of the same age. 



The large stipe, fig. 3, Plate iv, is from the same beds as fig. 1 ; and 

 from its exterior markings, I infer that it is a larger individual of the same 

 species. The upper part of the stem is gradually expanded, and the broken 

 margin indicates its relation to the spreading frond above. The entire length 

 of the fragment is six inches, which, with the same proportions as the 

 smaller ones, would give the entire plant more than a foot in height. 



This species is the most common form known to me at this time. Frag- 

 ments of the spreading frond are common at Cuyahoga falls, and stems and 

 fragments of stems are of frequent occurrence at Richfield, Ohio, from 

 whence it was first brought by Dr. G. M. Kellogg. 



DICTYOPHYTON FILITEXTILE (n.s.). 



PLATE IV. FIG. 5. 



An impression of the hollow stem in sandstone presents a regularly 

 cancellated surface; the striae are sharp linear, and in three de- 

 grees of strength, every fourth one being more deeply impressed 

 or stronger than the others, while the central intermediate one is 

 stronger than the adjacent two. In the longitudinal direction there 

 is a slight angularity, or greater prominence, at regular intervals 

 of every eighth stria. 



The figure is drawn from a cast in the natural mould. In the same piece 

 of stone is a second fragment of a character similar to the one illustrated. 



The stem appears to have been more uniformly cylindrical, and the striae 

 are sharper than in the stems of D. newberryi. The substance of the stem 

 was apparently very delicate, and nothing is known of the upper portion of 

 the frond. 



Geological formation and locality. In the Chemung group of Steuben 

 county, N.Y. 



DICTYOPHYTON REDFIELDI (n.s.). 



PLATE V, FIG. 1 ; PLATE V A, FIG. 1 ; AND PLATE IV, FIG. 6, 



The large hollow stem has a spreading base, and is gradually con- 

 tracted to a little above the middle of its length, where it is more 

 expanded into a broad somewhat funnelshaped frond, the full 

 extent of which is not known. Surface cancellated by fine, almost 

 even, threadlike striae; while on one side there appears to have 

 been, at regular intervals, stronger transverse striae with finer in- 

 termediate ones, but no indications of stronger longitudinal striae. 



