1876.] 



Auditory Ossicles of the Mammalia. 



105 



Canidae the manubrium forms a bold curve with the concavity forwards, 

 and its outer surface, towards the membrana tympani, is broad through- 

 out ; in the felidse this curve hardly exists, and the outer aspect is very 

 narrow. In Hycma and Proteles the processus muscularis of the malleus 

 is very stout, blunt-pointed, and almost straight, and the manubrium is 

 curved as in the dogs ; its outer aspect is broader near the tip than at 

 the base in the Hycena, but broad throughout in Proteles. Hence the 

 mallei of these animals are more canine than feline, particularly that of 

 the Aard-wolf. Among the Canidse themselves Lycaon most approaches 

 the HysenidsB in the stoutness of its processus muscularis. In all the 

 above families, as well as in the Civets and in the Crypto^rocta, the 

 incus is small with slender crura, the posterior almost as long as the 

 processus longus, and the stapes is small and triangular. 



The Procyonidse, ^EluridsB, Yiverridae, and Cryptoproctidge resemble 

 one another in the ill-development of the processus muscularis of the 

 malleus, which, however, is never quite absent. The outer surface of the 

 manubrium in those families is narrow, as in Felis and U rsus. In the 

 JElv.rus and the ProcyonidsD, including Bassaris astuta, the incus has a 

 very short processus brevis, as in the bear ; in the Civets and Crypto^ 

 procta that crus is well developed, as in the cats and dogs. From the 

 above observations it follows that C rypto'procta is more Feline than 

 Canine, and more Viverrine than Eeline, in the character of its malleus. 



The weasels and the other Mustelidse are known from the rest of the 

 Fissipedia by the extreme narrowness of the lamina of the malleus, and 

 the very wide angle which the rather short manubrium forms with the 

 neck. The processus muscularis of the malleus is as well developed as 

 in the cats and dogs ; but the Mustelidce exceed the bears and the Pro- 

 cyonidse in the extreme ill- development of the posterior crus of the incus. 

 In the smaller weasels the base of the stapes is generally bullate. 



In the genera Herpestes and Suricata the malleus differs in form from 

 the type existing in the other Viverridse and the rest of this suborder. 

 The head of that ossicle is more developed, but there is hardly a trace of 

 a lamina. The processus muscularis is not situated on t>.e neck close to 

 the root of the handle as in the other Carnivora, but on the inner edge 

 of the manubrium itself. The incus is of the form seen in Felis, Viverra^ 

 and Canis, not of the ursine type. 



The ossicula of the Pinnipedia are large, well marked, and readily dis- 

 tinguishable in the different genera. 



The Otariidae are exceptional in having very small ossicula, but they 

 are of dense consistence as in the true seals. The malleus has a head 

 which is concave anteriorly, and the articular surface is of the same pro- 

 minent character as in Phoca. The neck is constricted, and the manu- 

 brium rather longer than in the other Pinnipedia. The incus differs 

 from that of all other members of this suborder ; in its non-diA^ergent 

 posterior crus and its long, far-reaching slender processus longus it is 



VOL. XXV. I 



