﻿158 Cincinnati Society of Natural History. 



clay beds associated with coal, wherein arc intercalated shaly fragments, 

 colored in concentric zones by penetration of iron in such a way that they 

 exactly represent the appearance of the fossils described by the English 

 Authors. The zones, about two millemetres wide, are of different hard- 

 ness, and the soft white ones being easily disintegrated, they form a series 

 of alternately elevated and depressed bands, similar to those described as 

 characters of the Polyporites of the coal." 



Having thus disposed of the only form ever previously referred to 

 Fungi*, he goes on to describe under the name of Rhizomorpha Sigfflafw . 

 a specimen found in the Coal Measures of Pennsylvania which he consid- 

 ers a fungus. It was found under the bark of a species of Sigillaria, and 

 is described as having an irregularly formed stem, "round, polygonal, 

 elongated and linear, or amorphous,"' with diverging simple or forked 

 branches, club-shaped toward the ends, or flattened by compression. 



Some time since, I read before this Society j a paper on the " Fucoids 

 of the Cincinnati Group, " in which I endeavored to show that none of the 

 so-called marine plants found in this locality were of a vegetable nature ; 

 but that they are referable either to inorganic causes, such as water wash- 

 ings, or to tracks, trails, Graptolites, or impressions of organisms. It is my 

 opinion that the fossil under consideration has been erroneously referred 

 to the vegetable kingdom : and that, instead, it should be regarded as a 

 burrow made under the bark, where found, by some species of insect. 



That it is not a vegetable is rendered probable from the fact that the 

 mycelium of a fungus, which the fossil is supposed to be, is of a character 

 little likely to be preserved. It is liable to decay in a short period, and 

 even the spot it has occupied becomes indistinguishable from the rest of 

 the wood. It is otherwise with an excavation made by an insect. This, 

 living under the bark, eats it away along certain lines, and leaves behind 

 a cavity which remains as a scar, and if the tree under the bark of which 

 it has burrowed be preserved as a fossil, the burrow stands an equally 

 good chance of preservation. 



That the fossil considered is a larva burrow, is rendered still more 

 probable when it is remembered that under the bark of living trees, simi- 

 lar excavations are found. Those made by species of Scolyius burrowing 

 under the bark of species of Hickory, possess the same characteristics and 

 appearances as the fossil. The main burrow is generally straight, although 



* In the " Bull, of Torrey Bot. Club " for June, 1885, (Vol. XII, p. 64) is a note on a f^sil 

 fungus found by Messrs. B. Renault and E. E. Bertrand in the tissues of the nucleus of Spharrosprr- 

 mum oblongum, of. the Coal Measures. The fungus belonged among the Chy tridiaeeie. 



f See this Journal, Vol. VII, pp. 124, 151. Oct., 1884— Jan., 1885. , 



