OF THE MAMMALIAN OSSICULA AUDITUS. 483 



In the smaller species of Dasyures, as, for instance, Dasyurus maugcei (PL LXIV. 

 fig. 16), the malleus is of very similar character to that of Thylacinus, though the neck 

 is not so holdly curved, and the lamina is narrower. The incus and stapes are identical 

 with the corresponding ossicles in the Tasmanian Wolf. Not a trace of any aperture 

 exists in the stapes. 



In Dasyurus ur sinus the malleus has a larger and rounder head, a much narrower 

 lamina, and, in particular, a much stouter and stronger manubrium, than in the above- 

 described species ; its sides are of considerable breadth near the root. The processus 

 longus of the incus bears a small Sylvian apophysis on an extremely thin and fragile 

 pedicle. The stapes is absolutely columelliform. The two inner ossicles are smaller in 

 an adult D. ursinus than in a full-grown Thylacinus ; but the malleus of the former is of 

 nearly the same size and of more solid make than in the Tasmanian Wolf. 



The malleus from a small Phascogale (PI. LXIV. fig. 18) in the collection resembles 

 that of Dasyurus in every respect; the lamina is wide. The processus brevis of the 

 incus is very short ; the stapedial crus bears a similar but proportionally larger Sylvian 

 apophysis compared with the same in Thylacinus. The little stapes is columelliform 

 without an aperture ; the stapedius-muscle attached to it is very large, as in most of these 

 animals. 



In Myrmecobius the malleus is of the same light build as in the Thylacine. The head 

 projects considerably above and in front of the lamina. The neck is very long, but 

 not more curved than in Dasyurus. The lamina is as wide and smooth as in the Tas- 

 manian Wolf, and hence more extensive than in the Dasyure and Phascogale ; it joins the 

 processus gracilis to form the usual long curved process applied to the tympanic ring. 

 The manubrium is of the same form as in the other Dasyures ; but its outer angle (which 

 in this family is generally sharper than in the Kangaroos) is conspicuously bent out- 

 wards so as to form a genuine processus brevis. The incus has an extremely short pro- 

 cessus brevis, a deeply cut articular surface as in other Dasyures, and a distinct Sylvian 

 apophysis on a long pedicle. The stapes is perfectly columelliform. 



Among the Phalangistid^e the malleus of Phalangista vulpina (PI. LXIV. fig. 20) 

 may be selected as a typical example. The head, though small, is better developed than 

 in the Dasyures ; and though it does not rise high above and in front of the facets, its 

 upper surface is wide antero-posteriorly, projecting backwards over the articular surface. 

 This latter is rather deeper cut than in the Dasyures ; and the upper facet is very wide, 

 especially vertically. The neck is rather short, but curved, the lamina rather narrow ; 

 and the processus gracilis is of equal or almost equal breadth throughout, so as to look 

 like a curved piece of steel ribbon. This is much more like the form of that process 

 in the Didelphyidae than in the Dasyures. The manubrium is almost straight, and is 

 slender and little recurved at the tip, as in the Kangaroos; the angle corresponding to 

 the processus brevis is rather obtuse. 



A notable feature in this family is the large size of the incus. In Phalangista vulpina 

 it is decidedly slightly larger than in Macropus major, and larger than in any Dasyure, 

 nearly twice the size, in fact, of the same ossicle in Thylacinus ; yet the malleus of an 

 adult Vulpine Phalanger is hardly larger than that of Dasyurus maugcei, where the incus 



