Page 16 - maxson1928

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Nebraska. arei similar. The tooth from the lTint Canyon beds is much larger

than it is in the type species of the former and somewhat larger than in

the latter~ Merychippus intermontanus Merriam from the Barstow Miocene

of the Mohave Desert is similar in pattern but somewhat smaller in size.

The major portion of a tooth which may be upper yremolar four is

assigned to this species. It is a large tooth and comparable in size to

teeth of the two Barstow forms, Me_rychippus intermontanus and J\,:erychippus

calamarius stylodontus. The protocone is strongly united to the

protoconule, a character which seemingly indicates a relationship with

M. intermontanus since in M. calamarius stylodontus the protocone is

often separate from the protoconule until the crown is reduced to a

height measurement less than the width. rl'he hypocone is not prominent

and is attached very solidly to the metaconule. A small pli caballin

is present.

The two lower premolars (see Plate I. Figure 3.) have the simple

pattern shown in M. seju.nctus and in M. intermontanus after considerable

wear. 'They are much larger than the corresponding teeth of M. sejunctus

and are heavily cei"iented. The metaconid-metastylid column in P is
2
narrow and closely united to the base of the crown. 'l'he entoconid is

obliquely truncated.

Cor.1:parative 1.Ieasu.rements

2 M. intermontanus M. intermontanus Jl. c. stylodontus
P- No. 30042 U.C. {Mint Canyoril (type) ( type)

Antero-Josterior dis.meter -- 32.1 -------- a27 -----···• 28.9

Transverse ft 2,~ .2 -------- -------- 24.2

Height ----------------- 29.0 --------- 30 ( P~) ---

Note: "all indicates that the measurement is approximate.