1897.) Fossils and Fossilization. 21 
It is rare to find fossil bones silicified, and this replacement 
so common in vegetable or invertebrate remains is very un- 
common. The bones of vertebrates are often found distorted 
from having undergone softening from their partial macera- 
tion in water, and become almost unrecognizable upon their 
extraction. 
“The Maidstone Iguanodon,” says Mantell, “is a striking 
example of this kind ; in the entire series of bones exposed, 
there is scarcely one that is not more or less altered by com- 
pression. The humerus and thigh-bones especially are com- 
pletely distorted ; the vertebrate pressed almost flat, or squeezed 
into abnormal shapes, etc.” Bones of the Moa, taken out at 
North Island, New Zealand, were of the consistency of putty, 
and could be broken or kneaded almost like columns of clay, 
but hardened upon exposure and drying. 
In this connection, relative to the accumulation of bone de- 
posits in the past, some observations of the recent African 
traveller, J. W. Gregory, are of vital interest. He says (The 
Great Rift Valley, J. W. Gregory, p. 268) “here and there 
around a water hole we found acres of ground white with 
the bones of rhinoceros and zebra, gazelle and antelope, jackal 
and hyena, and among them we once observed the remains of 
alion. All the bones of the skeletons were there, and they 
were fresh and ungnawed. The explanation is simple. The 
year before there had been a drought, which had cleared both 
game and people from the district. Those which did not mi- 
grate crowded round the dwindling pools and fought for the 
last drop of water. These accumulations of bones were there- 
fore due to a drought and not to a deluge.” 
The fossilized remains of marine vertebrates are not uncom- 
mon, and in the cretaceous beds of Wyoming they have been 
preserved with remarkable completeness, eliciting the remark 
from Prof. Marsh that “ he noticed the skeletons of six of those 
mighty swimming lizards—the mosasaurs—each eighty feet 
in length, in sight at one time.” 
The fish beds at Twin Creek, Wyoming, the fish remains in 
Ohio, including the great Dinicthys, those at Sunderland, 
Mass., together with numerous indications of marine creatures 
