FLINT CHIPS. 599 
but unfortunately none of the skulls were preserved ; they had been broken be- 
neath the feet of countless deer and antelope that had come to the lake for water. 
We got a great many teeth and bones. They were all scattered. One party 
under Prof. Condon, of the State University, had been at the locality before us. 
The mammaUan bones were three species of the Horse ; three of the Llama ; one 
new species of a sloth, Mylodon ; the elephant ; a beaver-like animal, and some 
carnivores. We got great quantities of fishes that varied in size from a trout to 
a salmon or larger ; also a great many bones of birds in size from a sand piper to 
a stork. Among them was the Canadian goose. There were piles of land-shells 
that looked like snow-drifts. The bones were but little petrified and were of the 
pliocene age. The animals had all doubtless perished under a storm of volcanic 
ashes and sand from an active volcano near by. 
We found numbers of arrowheads, polished and made from volcanic glass or 
obsidian. We had thought at first that they might be contemporaneous with the 
bones, but I found near the deposit, between some huge sand banks, in the re- 
mains of an old Indian village, near which one arrow-maker had his abode, great 
quantities of chips of obsidian, perfect arrowheads and those partly finished, 
with drills, knives, pestles and mortars, and a pile of whitened rabbit and other 
bones. We iound part of an Indian skull also. One peculiarity I noticed in the 
desert was that all the springs were on the tops of rounded knolls, which led me 
to think that perhaps water would come to the surface from artesian wells. If that 
be the case, this country will one day become a fertile land. We got over a 
thousand pounds of fossil bones from this locality, all of which have been de- 
scribed by Prof. E. D. Cope in the Bulletins of the U. S. Geological Survey. 
FLINT CHIPS. 
G. C. BROADHEAD. 
In the January number of the Review Dr. Child asked about "gun-flints," 
I therefore thought I would chip off a few notes concerning 7?/^/ and other some- 
what similar rocks. 
Flint is a uniform impure variety of silica allied to chalcedony. It is crypto- 
crystalline and of opaque dull colors, generally grayish, smoky-brown and brown- 
ish-black ; is easily broken and breaks with a flat conchoidal fracture and sharp, 
cutting edge. It is feebly translucent, of a homogeneous texture, bears polishing 
but possesses little lustre. 
The flint of the chalk formation largely consists of the remains of infusortcs 
and sponges, and recent investigations have in a great measure confirmed the 
theory that most flint concretions and chert concretions are remains of sponges. 
— the fossil spicules of sponges ; they have in fact been classified and assigned to 
genera and species. 
Hornstone resembles flint but is more brittle. Chert is a variety of horn- 
