20S Mr. R. I. Pocock on the 



middle of the inner wall of the bulla (most of the genera), or 

 set far back only a little way in advance of the foramen 

 Iacerw7i posticum [Cynictis). In some Felidse (e. ^g^., a skull 

 of F. jaguarondi) it is only a little closer to the foramen 

 lucerum posticum than in Cynictis. In others it lies back so 

 as to open within that fossa. 



(2) In the Viverridse the canal its(4f may be a long com- 

 pletely bony tube traversing the wall of the bulla [Mwigos and 

 allied genera), or it may be a complete bony tube only at its 

 anterior end and an open channel in the bulla posteriorly 

 {Genetta, Pagvma), or it may be an incomplete tube or 

 an open channel throughout its length in thebullH [Civettictis, 

 Viverricuta, Viverra), or it may form a very distinct ridge 

 running obliquely across the cavity of the bulla (Cynogale). 

 In the Felidse it is, as a rule, an open channel, only excep- 

 tionally being a closed bony tube in its posterior half. 



(3) In the Viverridse the orifice by which the artery enters 

 the base of the skull after leaving the tympanic canal may 

 be entirely cut off from the rest of the foramen lacerum 

 medium and fully exposed on the basisphenoid (Mungos, 

 Cryptoprocta, Fossa, Galidictis, Arctogalidia), or it may be 

 continuous with the foramen lacerum medium behind and form 

 a deeper or shallower notch in the basisphenoid, the anterior 

 end of this notch being sometimes plainly visible in front 

 of the bulla [Arctictis, Diplogale, Paradoxurus) , sometimes 

 overlapped by it and only visible by looking beneath the 

 bulla {Genetta, Viverricula, Nandima). In the Felidse the 

 orifice always notches the basisphenoid, as in the genera just 

 mentioned, but it is never visible from the surface, because 

 the overlying portion of the bulla forms here a bony contact 

 or fusion with the basisphenoid. 



The combination of these characters — namely, the fusion 

 of the bulla to the basisphenoid and the consequent complete 

 concealment of the foramen lacerum medium by which the 

 internal carotid enters the skull after leaving the bulla — is 

 apparently the only positive feature that can be substan- 

 tiated between the Viverridse and the Felidse so far as the 

 structures under notice are concerned. 



EXPLANATION OF THE PLATES. 

 Plate X. 

 Fig. 1. Base of cranium of Viverricida tnalaccensi's, with bulla of leftside 

 removed and bristles passed through the eustachian tube and the 

 carotid canal of the right side, ov., foramen ovale; <//., glenoid 

 foramen ; fin., foramen lacerum medium running from the 

 periotic and deeply notching the basisphenoid ; st., stylomastoid 

 foramen with the fenestra rotunda on its inner side and the 

 fenestra ovalis just in front ; per., periotic pierced by these two 



