Among the Marsupialia the Tasmanian devil (Sarcophilus) gives a very
good idea of a generalized mammalian brain, and shows a large
development of the parts concerned in the sense of smell. The most
important advance on the monotreme brain is that the calcarine fissure
has now appeared on the posterior part of the mesial surface and
causes a bulging into the ventricle, called the _calcar avis_ or
hippocampus minor, just as the hippocampal fissure causes the
_hippocampus major_ (Gervais, _Nuov. Arch. Mus_. tom. v., 1869;
Ziehen, _Jenaische Denkschr_. Bd. vi., 1897).
[Illustration: From _Cat. R.C.S. England_.