166 



DR. E. BAY LANKESTER ON THE 



Detailed Description of the Skull and Limb-bones. 

 By R. Lydekker, F.B.S. 



From jElurus (in which the formula of the clieek-teeth is p. f , m. f , and the total 

 number of the dentition 38) JEluropus differs markedly, not only by the absence of an 

 alisphenoid canal, but likewise by the presence of a third lower true molar ; in the latter 

 respect resembling the Ursidse, and more especially the extinct genus Hyanarctm, in 

 which the upper molars have short and broad crowns, and the last lower molar is much 

 less elongated than in the genus Ursiis, being, indeed, considerably shorter than the tooth 

 in front of it. The carnassials of Hycenarctus likewise come uuich closer to those of 

 ^■■Eluropus than to the corresponding teeth of TJrsiis ; the upper one of the former genus 

 having a trilobed blade, owing to the development of a style in front of the protocone. 

 Its tubercular portion also carries a small hypocoue, which, however, is coalesced with 



-at- 



^.ci 



-^ 



B 



D 



cl 



Left upper carnnssial teeth of Raccoon (A), Himala_yan Long-tailed Panda (B), Great Panda (C), Cave-Bear (D), 

 and Hij(TnarctHS (E). «, protocone ; 6, paracone ; c, metacone ; (/, hypocone ; c, anterior stylo. 



the protocone (fig. E). In ^Bluropus, on the other hand, the upper carnassial (which, 

 contrary to the statement of Sir William Flower, lias an inner root) has a large and 

 distinct hypocone situated behind the protocone, from which it is completely separate ; 

 this being a character it possesses in common with ^Bluriis and the American Procyonidae, 

 but found in no other Caruivora. In the Raccoon and its American relatives the 

 anterior style of this tooth is, however, much reduced, and as the metacone is also 

 relatively small, the blade, although still trilobed, is mainly formed by the paracone. 



The lower carnassials of ^Inropus and ^Blurus are likewise constructed ou the same 

 general plan, being remarkable for the large size of the metaconid and entoconid. In 

 this feature they are essentially raccoon-like *, tlie main difference being that the 

 entoconid is double — distinctly so in jElurus, but rather less clearly in jElnropus. In all 



* These features are well shown in the series of sectorial teeth of Carnivora exhibited on one of the pillars of the 

 Lower Mammal Gallery of the Natural History Museum, from which figs. A tj E were taken. 



