179—2 INDIAN TERTIARY AND POST-TERTIARY YERTEBRATA. 
character of the cheek-teeth the presence of hut a single true molar in the upper 
jaw. In all the genera the lower carnassial (mTT) is characterized by its 
great relative length ; and the premolars, are generally sub-conical teeth with 
the fore-and-aft talons very slightly developed. The mandible of the larger 
and stronger forms is in general characterized by its relative shortness and 
depth, and the straightness of its inferior border. 
There is a considerable degree of variation in the development of the 
upper carnassial $( pm. 4 ) relatively to the other cheek-teeth in the different 
genera. In some forms ( Meles , Arctonyx , Gonepatus ) this tooth is much shorter 
than the true molar f m. 1 ), whence the upper dentition may be termed 
meionocreodont } In other genera ( Helictis , Taxidea , Mydaus, Mephitis ) pm. 4 is 
about equal in size to m. 1 , whence these genera may be termed mesocreodont. 
In the remaining genera {Gulo, Galictis, Ictonyx, Mellivora ) pm. 4 is much 
longer than m. 1, whence they may be termed megalocreodont. In the 
meionocreodont forms the lower carnassial (mTl) is relatively longer than in 
the megalocreodont forms, being developed in correspondence with the increased 
relative size of the upper true molar ( m. 1 ) in the former. The rate! and 
the badger afford extreme examples of this difference ; the length of m. 1 
in the former being about 1^ times that i of pm. 4, whereas in the latter it 
is nearly 2~ times the length of pm. 4. The glutton is intermediate in this 
respect, the length of mTl, being nearly twice that of pm. 4. Generally it seems 
that in the meionocreodonts the length of mTT is more than twice that of pm. 4, 
whereas in the megalocreodonts the length of the former is never more, and may 
be considerably less than twice that of the latter. 
For the purposes of the present memoir the most important dental character 
is that while in Gulo and Mellivora the hinder talon of the lower carnassial is 
bluntly trenchant, in all the other forms this part is hollow, and surrounded with a 
rim, or ridge of cusps : this character is most marked in Meles, Taxidea, Arctonyx, 
Mydaus, and Ictonyx. 
Fossil forms . — The above-mentioned group appears to be extremely poorly 
represented in previous geological epochs, the only fossil forms, except those 
described below, with which the author is acquainted, being the existing Gulo luscus 
and Meles taxus from the pleistocene of Europe. ; a species of Galictis and Mephitis 
from the caverns of Brazil ; Paloeomephitis and Promephitis from the upper tertiaries 
of Europe ; and one species of Taxidea from the pliocene of North America, 
described by Professor Cope under the name of T. sulcata. As the Indian fossil forms 
described below belong to the genus Mellivora and an allied genus, for which the term 
Mellivorodon is proposed, it will be seen that the geographical distribution of the fossil 
forms in many cases agrees very closely with that of their living representatives. 
l These terms will he more fully explained in the sequel : they are compounds of “ creodont ”>=“ flesh ” or “ carnassial- 
toothed,” and are intended to indicate the relative size of the “ flesh ” or “ carnassial tooth.” 
