1889.] NATURAL SCIENCES OF PHILADELPHIA. 241 



sehr rasch erfolgen konnte, d. h. innerhalb des Zeitraums, welcher 

 durch die Fauna der Phosphorite begrenzt erscheint; ausserdem 

 sprechen auch anatomische Griinde gegen diese Annahme. Bei 

 alien diesen Formen ist namlich der zweite untere Schneidezahn 

 wie bei der Gattung Cynodictis und den Hunden, Mardern und 

 Zibethkatzen schon hinter den ersten und dritten geriickt, wahrend 

 die Schneidezahue hei den Katzen mit dem Kronenteil eine Reihe 

 bilden, ferner erscheint der vordere Teil des Unterkiefers nicht 

 abgestutzt wie bei den Katzen, sondern lauft spitz nach vorn zu, 

 und ausserdem sind audi bier die Schliisselbeine ganz wie bei alien 

 Hunden, Mardern und Zibethkatzen verloren gegangen, wahrend 

 die Katzen noch deutliche Rudimente derselben aufzuweisen haben. 

 Da aber die Nachkommen unmoglich in der einen oder andern 

 Beziehung dem ursprunglichen Zustand naher stehen konnen, als 

 ihre Ahnen, so wird die Filhol'sche Ansicht wenig haltbar er- 

 scheinen." 



Though not wishing to defend Filhol's views, it seems to me that 

 the anatomical objections which Schlosser urges against them are 

 of no great weight. It seems quite clear that the slender, tapering, 

 mandibular ramus is the original, primitive one; at least, it is 

 well nigh universal among the creodonts, and it is difficult to see 

 why the form which characterizes the feline lower jaw should not 

 have been derived from the slender ramus. At all events, the 

 hyenas, which Schlosser admits fo be closely connected with the 

 civets, have developed a mandible, which, in its anterior portion, is 

 very like that of the cats, and in this respect Oryptoprocta is just 

 intermediate between Proailurm and Feli* — a slight change further 

 in the same direction would reproduce the mandible of the cats. 



Necessarily correlated with the shape of the mandible is the ar- 

 rangement of the lower incisor series — here, again, it would appear 

 that the FelidcB present, so far as the Carnivora are concerned — not 

 the primary, but a modified condition, for in all of the creodonts 

 in which the condition of the lower incisor series is known to me, 

 the second one is either wanting, or lias been pushed back of the 

 6rst and third, just as in the dogs and civets. In this respect, also. 

 Hyoena agrees with the cats, as do some, at least, of the bears, and 

 it would appear to be a necessary consecpience of the widening of 

 the muzzle in the groups mentioned. 



As regards the presence of clavicles in the cats, it need only be 

 said that nothing is as yet certainly known as to their presence or 



17 



