II. — Notes on the Chemical Composition of the Silicious Tubes 



of the DeviVs Corkscrew, Daemonelix. 



By THOMAS HERBERT MARSLAND. 



In "Notes on a New Order of Gigantic Fossils," by Erwin 

 Hinckley Barbour, University Studies, Vol, 1, No. " 4, the 

 author says, in speaking of the structure of the corkscrew: — 

 "In nearly all specimens the large tubes and cavities are filled 

 with an interesting deposit of gelatinous silicic acid, of about the 

 hardness and texture of paraffine or castile soap. * * * 

 Its color ranges from aurora red to pink, blue, gray, and white, 

 being highly opalescent in some cases and dendritic in others. 

 On drying, the unbroken homogeneous mass is divided by 

 shrinkage cracks, and, losing its color, becomes white." 



In June of 1892, while a member of 

 the Morrill Geological Expedition of 

 that year, the writer first saw and made 

 observations on this interesting sub- 

 stance, and while on the expedition of 

 1895 began a careful study of it, with 

 the hope of throwing more light on the 

 identity of the Devil's Corkscrew. 



A number of excellent specimens 

 were obtained in the field. These were 

 immediately placed in bottles, tightly 

 corked, and sealed with beeswax, to 

 preserve the specimens as nearly as 

 possible in their natural condition. 



This gelatinous silica occurs not only 

 as a filling of the small, medium, and 

 large tubes found running through the 

 transverse trunk and the spiral of Dae- 

 monelix, but also in sheets and masses 



Fig. \. 



Fip:. 1. — A specimen of Dae- 

 monelix partly dup; out, se- 

 cured by the writer for the 

 Morrill Geological Kxpedition 

 of 1>U2, in the bluffs of the Ni- 

 obrara Uiver. The figure to 

 the right shows a section of 

 the " rhizome" of an adjoining 

 specimen which was destroyed 

 in securing the first. The 

 white horizontal bar is gelati- 

 nous silica. The stippled 

 areas are partly structureless 

 sand rock. Height 1.5 meters. 

 (5 ft). 



University Studiks, Vol. II., No. 2, January, 1897. 



125 



