OF THE MAMMALIAN OSSICULA AUDITUS. 435 



the neck ; and a sharp angle is seen where the latter commences, very like the projection 

 which actually exists in the middle of the neck of the malleus of Sorex. But, by 

 examining these ossicles in the Shrew and in Myogale by means of a lens, it will 

 be seen that in the former the articular surface is not deep vertically, but the neck is 

 long and sharply angled, whilst in the Daesman the articular surface is long, and the 

 neck short. The lamina is wider than in Sorex ; the processus gracilis is slender and 

 partially ankylosed to the tympanic bone in the adult. Close to the root of the manu- 

 brium there springs from the inner side of the neck a round-headed process (PI. LXII. 

 fig. 3, oa) mounted on a long pedicel, to which I find that the tendon of the tensor 

 tympani is attached in the recent skull. 



The manubrium is long, and forms a very obtuse angle with the neck ; it is much 

 flattened laterally, and rather broad at the base, so as to be of the sabre-like outline 

 frequent among Rodents. The outer angle of the base is blunt and slightly bent towards 

 the neck ; the same aspect of the rest of the manubrium is sharply bordered from the 

 sides, and distinctly dilated at the extremity. 



It is instructive to compare the malleus of Myogale with the corresponding ossicle in 

 Gymnura, which possesses an undoubted orbicular apophysis homologous to that of 

 Sorex, and an equally distinct processus muscularis. The latter process, moreover, 

 actually coexists with the former in many Shrews, or at least is represented by a 

 tubercle. 



The attachment of the tensor tympani tendon to the single process in Myogale makes 

 that projection a functional analogue of the processus muscularis; but since it projects 

 backwards, as the orbicular apophysis does in Gymnura, where the muscular process 

 points inwards and forwards, it seems to me that this solitary process of the Daesman 

 must be considered as a homologue of the orbicular apophysis of the Shrew and Gymnura, 

 serving functionally as a muscular process, the true representative of the latter being 

 suppressed in this animal. 



The incus much resembles that of Sorex ; but the body is better developed, especially 

 posteriorly. The processus brevis is very short and non-divergent ; the stapedial crus is 

 long, straight, and ends in a rather large discoidal Sylvian apophysis. 



The stapes has a very wide aperture, occupied in the recent skeleton by a large bony 

 canal. The head is broad and shallow ; there is a small tubercle for the insertion of the 

 stapedius tendon. Both crura are very slender and divergent ; the anterior is consider- 

 ably the more curved. The base is of necessity wide horizontally ; it is distinctly concave 

 towards the vestibule, without any bulla or umbo. 



The ossicula of M. pyrenaica are very similar to those of the Russian Myogale. In 

 this animal and in the skulls of the latter and larger species I have always found a very 

 stout bony canal between the crura of the stapes. Hyrtl {op. cit.) observes : — 



" In Sorex and Myogale the vessels run exactly as in Talpa, without, however, being 

 enclosed within the tympanum in bony canals." In describing the vessels of the tym- 

 panum in the Mole, he had previously remarked that " the bony canal does not fill the 

 three-cornered aperture of the stapes ; on that account the stapes can be moved up and 

 down on the canal like a ring on the finger." If this be " exactly " the case in spe- 



