PLANTS. 



GENUS PAL^EOCHOKDA. 



PALJEOCHORDA PRIMA, n. sp. 



Plate 1, fig. 2. 



Plants, the remains of which, as preserved on the surface of the rock, 

 consist of narrow, linear, grass-like stipes, coiled or twisted without 

 any regular order, leaving by their removal or decomposition flattened 

 depressions of from one line to two lines in width and of an indefinite 

 length, with rounded or obtusely- pointed extremities. 



The examples in the collection before us are coiled, forming irregular 

 curves, usually enrolled, but sometimes sigmoidal. The surfaces are 

 smooth and structureless, presenting no marking whatever, although 

 the substance is usually of a somewhat lighter color than the surround- 

 ing rock. The terminations are usually sharply rounded, and the whole 

 appearance is more that of the impression of an Annelid than of a plant, 

 though it is difficult to conceive of the preservation of anything other 

 than a plant to leave such markings. We have referred them to the 

 above genus, presuming them to be congeneric with those figured by 

 Professor McCoy in his Synopsis British Palaeozoic Fossils, plate 1 A, 

 fig. 3, although they are not elevated or rounded bodies, but flattened 

 stipes. 



Formation and locality. In the plant beds of the Potsdam formation 

 (probably Upper Potsdam or Calciferous), Head of Red Water Valley, 

 Black Hills, Dakota. 



GENUS PALJ]OPHYCUS, Hall 



PAL^EOPHYCUS OCCIDENTALS, n. sp. 



Plate 1, fig. 3. 



Remains consisting of strong, subcylindrical, flexuous stems or roots, 

 covering the surface of the sandstone. The steins are more or less 

 rounded, although frequently quite flattened, and varying in diameter 

 from one-fourth of an inch to one inch, frequently bifurcating and some- 

 times dividing into threes. They are commonly interlaced with each 

 other, but do not appear to coalesce, but are simply overlapped 5 the 

 surfaces, although sometimes quite smooth, are generally marked by 

 indistinct longitudinal pits and ridges of greater or less extent, fre- 



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