era _Eutamias_ and _Neotamias_ are more closely related to each
other than either is to _Tamias_.

TABLE 1.--CHARACTERS BY MEANS OF WHICH THE GENERA EUTAMIAS AND TAMIAS
CAN BE DISTINGUISHED

=======================================================================
Character | _Eutamias_ | _Tamias_
-------------------------------------+----------------+----------------
Shape of head of malleus. | not elongated. | elongated.
-------------------------------------+----------------+----------------
Angle formed by planes of lamina and | approximately | approximately
manubrium of malleus. | 90 degrees. | 60 degrees.
-------------------------------------+----------------+----------------
Position of keel on tip of baculum. | dorsal. | ventral.
-------------------------------------+----------------+----------------
Relation of hypohyal and ceratohyal | fused in | never fused.
bones of hyoid apparatus. | adults. |
-------------------------------------+----------------+----------------
Appearance in cross section of | flattened. | rounded.
conjoining tendon of anterior and | |
posterior digastric muscles. | |
-------------------------------------+----------------+----------------
Presence or absence of P3. | present. | absent.
-------------------------------------+----------------+----------------
Projection of anterior root of P4 in | buccal. | lingual.
relation to masseteric knob. | |
-------------------------------------+----------------+----------------
Length of tail in relation to total | more than | less than
length. | 40 per cent. | 38 per cent.
-------------------------------------+----------------+----------------
Width of longitudinal stripes. | subequal. | median pair of
| | light stripes
| | twice as wide
| | as others.
-------------------------------------+----------------+----------------
Length of lateral longitudinal light | outermost | both pairs
stripes. | pair short. | short.
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It must be pointed out here that the