418 MR. R. I. POCOCK ON THE EXTERNAL 



Bardenfleth appears to have been much influenced by Winge's 

 opinion on the homologies of the cusps in pm. 4 of the upper 

 jaw, which, admitting its correctness, shows that the structure of 

 the tooth in question lessens the evidence for the affinity between 

 Ailuropoda and Ailurus and strengthens the evidence for affinity 

 between the former and the Ursidse. The points are : — (1) The 

 antero-internal cusp of Ailurus corresponds to the postero- 

 internal cusp of Ailuropoda ; (2) the postero-internal cusp cf 

 Ailurus is unrepresented in Ailuropoda and the antero-internal 

 cusp of Ailuropoda is unrepresented in Ailurus ; (3) the postero- 

 internal cusp of Ailuropoda corresponds to the postero-internal 

 cusp of the Ursidse ; (4) the antero-external and antero-internal 

 cusps of Ailuropoda are unrepresented in the Ursidse — in other 

 words, pm. 4 of the maxilla of the Ursidse corresponds to the 

 posterior half of the same tooth in Ailuropoda, with the further 

 difference that the inner and posterior roots of this tooth in the 

 Ursidse are, except in abnormal cases, fused. Nevertheless, the 

 resemblances between this tooth in Ailuropoda and Ursidse do 

 not, in my opinion, justify the conclusion that Ailuropoda is a 

 member of that family. For, if the tooth in Ailuropoda is not 

 Ailurine or Procyonine, it is certainly not Ursine. It is peculiar 

 and stands by itself, so far as living Carnivora are concerned. 



Some of the characters cited as of systematic value by Lydekker 

 and Bardenfleth are too inconstant to be of use. Steno's fissure, 

 the cleft between the anterior palatine (incisive) foramina, is 

 cited by Lydekker as diagnostic of the Procyoninse, restricted to 

 the American genera, which have it, and the Ailurinse, including 

 Ailurus and Ailuropoda, which are without it ; and Bardenfleth 

 states that it is present in Ursus and absent in Ailurus and 

 Ailuropoda. The actual facts are as follows : — Even in the com- 

 paratively small series of skulls belonging to the Zoological 

 Society, I find this fissure present in an example of Ailurus, 

 where it is represented by a groove terminating in a foramen 

 which passes up into the nasal passage — a condition which it 

 commonly presents, even within the limits of the genus Procyon. 

 As for the Ursidse, it varies in size from a long cleft to a 

 minute orifice, through which a needle-point can only just be 

 passed. 



Lydekker, endorsing Lankesters statement, also draws attention 

 to the " important fact that Ailurus and Ailuropoda resemble 

 the American Procyonidse, and thereby differ from all other Car- 

 nivora, in the presence of two lobes or cusps on the inner or 

 tubercular portion of the upper carnassial." Even if he had said 

 " some of the American Procyonidse," the statement would not 

 have been true, because both Ilelictis and Taxidea, two of the 

 Mustelidse, have two cusps on the inner portion of the tooth. 

 Again, "jEluropus approximates to the Racoon in the absence of 

 postorbital processes of the frontals." This is not true, the frontal 

 postorbital processes being well developed in all the skulls of 



