There is too much risk of including bones that pertain to other species or genera, and of introducing thereby into the restoration a more or less erroneous concept of the animal which it represents.

The same criticism applies to an overly large amount of plaster restoration.
[Illustration: Fig.

42 .-- Bone-Cabin Draw on Little Medicine River north of Medicine Bow, Wyoming.

The location of the quarry is indicated by the stack of crated specimens on the left, and close to it the low sod-covered shack where the collecting party lived.
Beyond the draw lies the flat rolling surface of the Laramie Plains and on the southern horizon the Medicine Bow Range with Elk Mountain at the center.] In some instances the missing parts of a skeleton are not restored, because, even though but a small part be gone, we have no good evidence to guide in its reconstruction.

This gives an imperfect and sometimes misleading concept of what the whole skeleton was like, but it is better than restoring it erroneously.