It is unnecessary for the speaker to apologize for the incompleteness of this summary paper, for within the limits of time at his disposal no adequate treatment can be attempted.2 Simply an attempt has been made to set down in coherent form the main points which should be in the mind of every one who is attempting to determine the climatic environment of a fossil form or a group of fossil forms found in any definite bed.
The criteria suggested in this paper for the determination of the climatic environment are not such as might rationally be figured out in an office chair, but are such as have been used by the author in the field and are proven to be practical. Much that should be revealed, from all considerations of theory, is commonly hidden, for one reason or another, as every field-worker knows, but certain things can always, or . . .