394 MR. R. I. POCOCK ON THE EXTERNAL 



a semicircular flap of integument rising behind the adjacent free 

 edge of the pinna, its anterior rim being deeply emarginate. 

 Judging from dried skins, the bursa of Jentinkia is similar to 

 that of Bassariscus. I also find it present in dried skins of 

 Bassaricyon, but it appears to be less well developed than in 

 Bassariscus. The upper portion of the posterior flap arises 

 behind the margin of the pinna, but its lower portion is confluent 

 with it, and its anterior rim is lower and apparently not emar- 

 ginate. The only other genus in which it is present is Nasua, 

 where it has the form of a shallow pouch near the edge of the 

 pinna which bulges slightly at this point. A similar bulge on 

 the ear may be seen in Procyon, but in no example examined 

 was there a trace of the pouch, and there is no trace of it in 

 Potos or Ailurus. There is also no trace of it visible in the 

 mounted example of Ailuropoda in the Natural History Museum, 

 and it is absent in all the genera of Ursidee. 



If, as I believe, a well-developed bursa, such as is seen in the 

 Felidse and Canidse, is a primitive feature in the Carnivora — and 

 its presence in some of the genera of all the recognised families, 

 except the Ursidse, suggests that conclusion, — it follows that the 

 ear of Bassariscus is the most primitive type in the Procyonidse. 

 Next comes that of Bassaricyon, then of JVasua showing stages 

 in its suppression which has been achieved in Procyon, Potos, 

 and Ailurus. 



The following table summarises the characters of the ears in 

 the genera examined : — 



a. Bursa retained. 



b. Bursa marginal, at least the, upper end of the posterior flap 

 attached behind the adjoining edge of the pinna. 

 c. Lower end of posterior flap behind the edge of the pinna ; 



anterior flap emarginate ; ears large Bassariscus, Jentinkia . 



c'. Lower end of posterior flap confluent with edge of pinna ; 



anterior flap with low straight edge; ears small Bassaricyon. 



b'. Bursa a shallow pouch in front of posterior edge of pinna.. JSTasua. 

 a'. Bursa suppressed. 



d. Ears large, expanded, and more or less pointed Procyon, Ailurus. 



dL Ears small and rounded Potos. 



By this table Ailuropoda would fall alongside Potos under the 

 heading d' . In the Ursidae also no trace of the bursa remains 

 and the ears are always rounded. They may, however, be com- 

 paratively large and rounded as in Selenarctos * tibetanus, or 

 small as in Helarctos malayanus. 



* Mr. A. de Carl Sowerby has pointed out to me that Heude applied this generic 

 name to this Oriental bear in 1901 (Mem. Hist. Nat. Chinois, v. pt. 1, p. 2). The 

 later name Arcticonus, which I gave to it in 1917 (Ann. Mag. Nat. Hist. (8) xx. 

 p. 129), lapses, therefore, as a synonym of Selenarctos. My excuse for missing this 

 point is that the then recorder of the Mammalia in the ' Zoological Record ' pur- 

 posely refrained from quoting Heude's work on account of its general worthlessness 

 in his opinion, 



