28 



Erwin Hinckley Barbour 



ten meters in length, even after an indefinite amount had been 

 weathered from each extremity. 



One who stands face to face with this great array of fossils 

 of prodigious size and intricacy and complexity of form can 

 not conceive that they could ever have been a simple plant, 

 notwithstanding the plant structure itself; but none the less the 

 facts will undoubtedly stand. Much less can we conceive that 

 they were "accidents" or "burrows." The "rhizome" is 

 quite generally loosely S shaped, though often straight. Some- 

 times it is characterized by noticeable enlargements at either 

 the upper or lower extremity, or in the middle. Sometimes 

 long slim processes or spurs project from it. 



In two distinct cases the expedition of 1895 found and se- 

 cured complete specimens of "Twin Screws." That is, the 

 transverse trunk bore two screws, one ascending, the other de- 

 scending. (Plate VIII., Fig. 4 ) The latter was smaller than the 

 former, and had not the rhizome in each case been sadly de- 

 composed it might have connected with still a third screw. 

 One screw was right-handed, the other left-handed in each. 



case. Had but one such ex- 

 ample been found we might 

 have counted it an accident, 

 but finding altogether three 

 such puts it almost out of the 

 reach of chance. These speci- 

 mens bring to mind forcibly a 

 sketch by Dr. Frederick C. 

 Kenyon, suggesting the possible method of reproduction in 

 Daemonelix.' (Fig. 20.) 



As early as 1892, the author found and sketched a " twin 

 screw." Two excellent specimens of this nature were added 

 to our collection last summer. The finer of the two was found 

 and secured by Mr. Jesse P. Eowe, assistant in the Department 



Fig. 20.— A sketch by Dr. F. C. 

 Kenyon, suggesting the method 

 of reproduction of Daemonelix. 



American Naturalist, March, ISStH. 



108 



