398 MR. R. I. POCOCK ON EXTERNAL 



ear in mammals, and by interlocking help to close the meatus 

 when it is capable of being closed. Mivart described the pinna 

 of the Common Cat ('The Cat,' pp. 295-296, 1881) and of the 

 Genet (P. Z. S. 1892, p. 51, fig. 12), adopting for the several 

 parts names originally applied to the human ear. An entirely 

 different nomenclature was, however, proposed by Boas in 1912 

 ('Ohrknorpel und iiusseres ohr der Saugetiere,' Kopenhagen). 

 in the following account I have attempted to show the corre- 

 spondence between these two systems and have, in the main, 

 followed that of Mivai't as being moi'e familiar and more in- 

 telligible, without wishing thereby to cast any reflection upon 

 the excellence of Boas' work. 



In Paradoxurus larvatus the cartilaginous ridges, with their 

 intervening fossfe, which strengthen the lower portion of the 

 pinna round the auditory meatus, resemble those of the Cat and 

 Genet in essential features. Two ridges run obliquely upwards 

 and forwards in front of the inferior orifice of the meatus 

 (adittts inferior of Boas). The outer of these, the posteron 4 of 

 Boas, carries a low elevation called the tragus by Mivart. The 

 inner, the anteron 6 of Boas, has a sinuous edge and runs higher 

 up the front of the ear than the outer or tragus-bearing ridge. 

 This inner ridge is called the post-tragns by Mivart in the case 

 of the Cat, but in his figure of the Genet's ear it is marked 

 tragus. Two ridges similarly run obliquely upwards and back- 

 wards from the inferioi' orifice of the meatus. The outer of 

 these, the jyosteron 6 of Boas, is produced inferiorly into a la,rge 

 angular process, the antitragus of Mivart, which fits into the 

 lower part of the fossa between the two anterior ridges when 

 the ear is closed. Above and Avithin the outer ridge lies the 

 inner of the two posterior ridges, which is much softer and less 

 well developed than the othei'S and shows a small swelling near 

 its lower end. This ridge, an integumental non-cartilaginous 

 structure, was not given a special name by Mivart, and was 

 merely desci'ibed as a "weiche Falte" by Boasw Nevertheless 

 it appears to be a constant feature in the ears, at all events, of 

 the Canidfe, Felida;, and Yiverridae, 



The four ridges above described, with their intervening fossfe, 

 form the anterior and posterior walls of the deep and spacious 

 fossa lying above the auditory meatus. This large fossa is defined 

 above by a transverse cartilaginous ridge, the piica principcdis of 

 Boas and the snpratragus of Mivart, the anterior end of which 

 is overlapped by the inner of the two anterior ridges. Towards 

 the middle of the ear it exhibits a marked swelling, and behind 

 this the ridge gradually fades away towards the inner side of the 

 inner of the two posterior ridges *. 



* The cartilaginous thiclieuing in tlie ear of the Carnivores, named pos^erow 4 ^J 

 Roas and tragus by Mivart, seems certainly to be the homologue of the " tragus " 

 in the human ear. But the thickening named "antitragus" by Mivart and 

 posteron 6 by Boas is not, according to this latter author, the exact homologue of the 

 human antitragus. This well-developed structure in man is part of another carti- 

 laginous ridge, the posteron 5 of Boas, which is at most feebly developed in the 

 Carnivores, being merely represented by a weak ridge lying below and on the outer 



