275—98 INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
Lepthycena. In the living representatives of the typical genus there is normally hut 
one true molar in either jaw, and each limb carries but four digits. In certain fossil 
forms ( Lepthycena , Hycenictis), mT2 is either always, or frequently, developed;' while 
m. 1 is relatively larger than in other species. These forms indicate an approximation 
to Ictitheriuvi, and thus connect the ■ family with the modern civets. 1 The genus 
Proteles is distinguished, among other characters, by the possession of five digits on 
the anterior limb, and connects the genus Hycena with the herpestine division of the 
preceding family ( Viverridce). 
The family is entirely confined to the Old World, with its head-quarters at the 
present day in Africa. 
Genus : HYiENA, Brisson. 
Including Grocotta, Kaup ; Crocuta , Gray ; Euhycena, Falconer, MSS.; 
Hycenictis , Gaudry. 
Dentition . — The normal adult dental formula of Hycena , in which, for palaeon- 
tological purposes, at all events, Crocuta 2 is best included, is I. -§, C. j, Pm. §, M. j. 
In certain fossil forms, however, pm. 1 is either occasionally, or normally, absent, 
while in others pm. 1 is normally developed ; and in others again m. 2 may be either 
occasionally, or normally, present. The range of variation in the dentition may, 
therefore, be expressed by the following formula: — viz. , I. •§, C. j, Pm. [|2j, M. . 
In typical forms the upper true molar is a comparatively small, transversely 
elongated tooth ; but there is considerable variation in the relative size of this tooth 
in the different species, and in some it is reduced to a minute subcylindrical crown, 
and may be shed at an early age, even if in some instances it be not totally absent. 
When fully developed this tooth is generally larger than in the cats, though occupy- 
ing a similar position : in typical forms it is different from the corresponding tooth 
in the dogs, which is always placed behind, instead of internally to, pm, 4 . The 
latter is a large tooth, which by the great development of the anterior 
talon has acquired a distinctly trilobed blade. In describing this tooth it will be 
convenient to refer to these three lobes as first, second, and third lobe, but it must 
always be remembered that the first lobe is unrepresented in the carnassial of the 
dogs, and corresponds to the talon-lobe of Bycenarctos ( plate XXX., fig. 2, a). The 
second, or middle, lobe corresponds to the first lobe of the dog’s tooth ( Hycenarctos , m ) ; 
and the third, or last, lobe, to the second or last lobe of the dog’s tooth ( Hycenarctos , p). 
This tooth is generally distinguished from the carnassial of the cats by the larger 
size of the tubercular portion ; but there is one species (H. eximia) in which this is 
small, and the distinction from the feline tooth is then very slight. The second and 
third upper premolars are large sub-conical teeth, with or without talons : 
the great development of the main lobe of these teeth in the typical forms 
distinguishing them from the corresponding teeth of the cats and dogs. The first 
1 See G-audiy, “Les Enchainements (lu Monde Animal, .etc. — Mammiferes Tertiaires,” p. 215, et. seq. 
2 Considered distinct by Prof. Mivart, op. cit. 
