50 CARNIVORES. 
The general habits of the grison appear to be very similar to those of the 
tayra. It is described as being the Carnivore most commonly encountered on the 
coasts of South America; but in Brazil it is stated to be less frequent than its 
cousin. By preference it appears to select the open country, although it may also 
be found in forests. It frequents plantations, and commits great depredations upon 
domestic poultry. Hollow trees, clefts in rocks, and deserted burrows, are its 
favourite retreats: but it is said that, when hunted with dogs, the grison will never 
attempt to climb, and invariably takes shelter under rocks, or beneath the roots 
of trees. Fossil remains of various species of this genus have been found in the 
eaverns of Lagoa Santa, in Brazil; while, what is more noteworthy, others have 
been obtained from the superficial deposits of the United States, thus indicating 
that the genus formerly extended far to the northwards of its present limits in 
Mexico. 
THE MARTENS, POLECATS, AND WEASELS. 
Genus Mustela. 
The martens and their near allies the polecats, stoats, and weasels, constitute 
the typical group of this subdivision. By many writers the large martens are 
separated as a genus from the smaller polecats, stoats, and weasels, the three latter 
being grouped together under the title of Putorius, but in this we are not disposed 
to concur. It is true that the martens have one more pair of premolar teeth in 
each jaw than their smaller relatives; but we cannot in any case attach much 
importance to such a difference, and its triviality is proved by extinct species, 
which exhibit a considerable amount of diversity in this respect. 
Regarding, then, all the animals above mentioned as constituting but a single 
genus, we haye to indicate the features by which the group is distinguished. 
In the first place, the number of teeth may either be the same as in the tayra, 
or there may be an additional premolar tooth on each side of both the upper and 
the lower jaw, thus raising the number of teeth to forty. The upper flesh-tooth, 
as already mentioned, differs from that of the tayra by having the lobe on its 
inner side placed close up to its front edge. With regard to external characters, 
the martens and weasels are distinguished from the members of the preceding 
genus by their habit of walking almost entirely on their toes (digitigrade), and 
also by their short and compressed claws being capable of partial retraction. 
Their tails are either long or of medium length, and more or less bushy. It may 
be added that the lower flesh-tooth of the martens and weasels is characterised 
by the small size or total absence of the cusp on the inner side of the second lobe. 
of the blade; and as the heel at the hinder end is also rather small and furnished 
with a cutting edge, the whole tooth consists of three main cusps, of which the 
two end ones are similar. Such a tooth is, therefore, totally unlike the lower flesh- 
tooth of a civet. 
eee ee The well-known European pine-marten, or yellow-breasted marten 
(M. martes), may be regarded as the typical representative of the 
martens, all of which possess the following features in common. First of all, they 
have four pairs of premolar teeth in each jaw; while the flesh-tooth of the lower 
