======================================================================= 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. -----------------------------------------------------------------------