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Cincinnati Society of Natural History. 



The heavy dashing of rain on the surface of mud will often make irreg- 

 ularly arranged elevations and depressions, with often a little channel lead- 

 ing the superfluous water to a lower level. This washing will frequently give 

 the surface of the soil an appearance very remotely resembling the branches 

 of a plant, and the cast will often be more misleading than the marks 

 themselves. Pieces of mud found in a fossil state having such markings 

 on them, have led to the establishment of a genus of so-called fucoids 

 under the name of Aristophycus. It was first described and figured by 

 Miller and Dyer, in No. 2 of " Contri. to Pal." (pp. 3, 4). One species, 

 A. ramosum (Plate VI., figure 2), and a variety, germanum, were described. 

 The species is described as consisting of a stem which divides and sub- 

 divides in an irregular manner. "The ramifications are sent off.'" say t*he 

 authors, "like the roots of a tree or shrub, without any determinate order, 

 while many of the smaller fibers inosculate like the veins in the leaf of a 

 tree." The variety differs from the species in having more numerous and 

 smaller branches. Neither one can be considered as entitled to a name of 

 any kind. There are no characters upon which to base the assertion that 

 it was a plant, and every indication that it was made by rain on the sur- 

 face of mud as before intimated. The same features may be seen on any 

 muddy surface after a moderately heavy rain. 



On other places of a mud flat, other indications of the action of water 

 are to be seen. On gently sloping banks small lateral rivulets will be seen 

 running into large ones, and these large ones into others still larger. The 

 smallest and the branch into which they run often assume a feather-like 

 form, the main channel representing the shaft and the small lateral ones 

 the web of the feather. 



From rocks of the Cincinnati group there has been described a genus 

 with the name of Chloephycus. It was established by Miller and Dyer, 

 in "Contri. to Pal.," No. 2 (p. 3), and one species (C. plumosum) was 

 figured and described. (Plate VI., figure 3.) The figure and the descrip- 

 tion, and the specimens themselves, indicate the character of the fossil. 

 It is nothing more than a mark, or a series of marks, produced in the way 

 already described by the running of water down a sloping bank into a 

 stream. 



If these channels, with their lateral branchlets in the mud, were en- 

 larged, a deeper channel would result. If a cast were then taken from the 

 depression, it would be rounded on one side and flat on the other. The 

 rounded side would be marked with lines running from the center toward 

 the edge, or overlapping irregularly along it. Now, the genus Tricho- 

 phycua was founded by Miller and Dyer, in "Contri, to Pal.," No. 1 



