This rat is very closely allied to _Mus decumanus_, and I think may
possibly prove an extraordinary local variety of that animal. Having but
one skin, and no skull, I am unable to satisfy myself on this point. Its
size, as will be seen by the admeasurements, exceeds that of the common
rat, or, rather, it exceeds ordinary specimens of that animal, for I
have seen _some_ which were equal to it.
“It was killed near Maldonado, where it frequented holes in the sand
hillocks near the shore. It is likewise found on the island of Guritti.
If ships are ever infested with these monstrous rats, the
above-mentioned localities are very likely places to have received
colonies by such means. An old male weighed fifteen ounces and three
quarters. The ears of this rat, when alive, were of a pale colour, which
made a singular contrast with the black fur of its body.”—D.