DaimoneJix and Allied Fossils. — James. 339 
which have given to science so man}' wonderful forms of life. 
The "corkscrews," as far as now known, occur over an area 
of 400 or 500 square miles. They have a vertical range of 
from 150 to 200 feet, according to Barbour. The tops of the 
hills are capped with sandstone, which is underlain hy a com- 
pact layer of light yellow flint, 18 inches or 2 feet thick. This 
is quarried for a building stone. Below this is a very homo- 
geneous and more or less coherent sand-rock, from 800 to 
1,000 feet thick, under which again is a layer of marl. The 
continuation of this marl to the northward forms the Bad 
lands of Hat Creek basin. It is in the upper 200 feet of the 
sand-rock underlying the flint that Daiinonelix occurs. 
Beyond a mention of the Miocene in connection with the 
fossils, Prof, Barbour does not discuss their geological posi- 
tion. But Dr. J. L. Wortman, in a paper read before the New 
York Academy of Sciences, Feb. 11, 1895, and reported in 
Science, (n. ser., vol. i, p. 306,) positively identifies the forma- 
tion with the Loup Fork division of the upper Miocene. He 
agrees with Prof. Barbour that the beds are of sedimentary 
origin. 
The opinions that have been advanced as to the nature of 
these fossils are various. Some have considered them as bur- 
rows of animals; some as having been made by shells; some 
thought them to be roots of plants, and some said they were 
Algse. That they are really of vegetable origin seems to be 
settled by the results of Barbour's studies of the tubules be- 
fore mentioned, which show evident traces of plant structure. 
One point seems to have been overlooked by all who have 
written upon them. They have been considered as unique 
and without resemblance to any other known fossils. As a 
matter of fact, however, they are not unique except in point 
of size. Similar fossils were described by Oswald Heer in 
1865* who called them ''screw-stones," and who published the 
figure here given. (PI. XT, Fig. 3.) He states that the fossils 
occur in Miocene strata in difl'erent localities in Switzerland 
and describes them as rods about the thickness of the finger, 
upon which are situated spirally wound branches of the same 
thickness. He considered them to have been made by boring 
shells, a number living together, and sending out the spiral 
*Die Urwelt der Schweiz, p. 4.38, 18G5. 
