112 FLORA OF SOUTHERN NEW YORK AND NEW ENGLAND. 



Rhizomorphs. 



PL VI, fig. 13. 

 Rhizomorphs, Hollick, Annals New York Acad. Sci., vol. 11, 1898, p. 423, pi. 38, fig. 1. 



These peculiar fossils are especially abundant in nodules of hard clay ironstone 

 at Tottenville, Staten Island, and I have found traces of them elsewhere. They 

 usually consist of filamentous carbonaceous matter, more or less branching, encased 

 in limonite. When the carbonaceous matter is absent only a tube of limonite 

 remains, and where these appear at the surface they give rise to pit-like markings. 

 The term rhizomorph was adopted for the reason that it was used by Dr. J. I. 

 Northrop in his description of somewhat simliar cylindrical structures in the coral 

 rocks of the island of Nassau, a which he concluded were caused by concretionary 

 structure around the roots of plants. In our specimens it is difficult to determine 

 what was the original position of the matrix, but apparently the tubes are more or 

 less at right angles to the original plane of deposition, in which case it is probable 

 that the rhizomorphs represent the remains of rootlets in place, and they therefore 

 may or may not be Cretaceous in age. Post-Cretaceous vegetation, whose rootlets 

 extend into a bed of Cretaceous clay, might equally well produce such a result. 

 Whatever their true nature and origin may be, however, these remains are exceed- 

 ingly characteristic and are worthy of description. 



Locality: Tottenville, Staten Island. Collected by Arthur Hollick. Specimen 

 in Mus. Staten Island Assn. Arts and Sci. 



a Trans. New York Acad. Sci., vol. 10, 1890, p. 16. 



