From The Collaborative International Dictionary of English v.0.48 [gcide]:
Chief hare \Chief" hare`\ (Zool.)
A small rodent (Lagamys princeps) inhabiting the summits of
the Rocky Mountains; -- also called crying hare, {calling
hare}, cony, American pika, and little chief hare.
[1913 Webster]
Note: It is not a true hare or rabbit, but belongs to the
curious family {Lagomyid[ae]}.
[1913 Webster]