Miscellaneous. B91 
entire size of the animal it shows a more gigantic development than 
in any other mammal. LExteriorly the malleus unites by an 
articulation with the sguama temporalis at a pot which appears to 
be depressed by the externally projecting hinder extremity of the 
zygomatic bone*. Nevertheless this union does not take place 
directly, but by means of a small acutely triangular ossicle, widen- 
ing from before backwards, which, on careful examination, proves 
to. be nothing but a portion of the incus which is amalgamated with 
the malleus}. 
_ Butif the malleus be examined on its upper surface, .a distinet 
suture appears to be present in places at the point where the long 
process unites with the malleus ; -and this leads us to expect that in 
yery young animals a dividing suture will be found here. 
At any rate it is of importance to the question of the interpreta- 
tion of the quadrate bone in birds, that inthe full-grown Tachy- 
_ glossus there is a bone, consisting originally of three or four sepa- 
rate pieces, which effects an articular union of the sguama temporalis 
with the os pterygotdeum and (at an earlier period) with the lower 
jaw. 
In Ornithorhynchus, in which the incus remains separate through- 
out life, the os tympanicum unites directly by the malleus with the 
squama temporalis; nevertheless it is to be observed that the incus 
situated above it is likewise united with the squama temporalis, 
which is the cause that, in this genus, it is difficult to remove the 
auditory ossicles in connexion. 3 
Here, therefore, we see, in the Monotremata, that.a-bone composed 
of two or more pieces.presents the same articular connexions:as the 
os quadratum in birds, that by these pieces, through the os tympa- 
mecum, is effected the union with the os_pterygordeum and the inner 
angular process of the lower jaw, whilst that with the sguama tem- 
poralis is effected by the malleus and incus, or by the incus alone. 
The question still remains to be solved, in the young Monotremata, 
whether the long process of the-malleus (occurring as .a distinet 
bone, and, in part, representing'a part'of the os tympantewm of the 
higher Mammalia) at-any time forms a condyle corresponding .to 
the outer cavity of the articular process of the lower jaw in birds.— 
Monatsber. Berl. Akad. der Wiss. Dec. 5, 1867, pp. 779-781. 
* To me the interpretation of this Peon bone, which attaches itself 
‘like a scale a the sqguvama temporalis, given by Laurillard’and Duver- 
noy seems to be quite correct, although it is remarkable that it assists in 
the formation of the cranial cavity, which, indeed, induced Mr. Owen not 
to agree in this interpretation, without, however, giving a better one 
char snirgasga Cycl. of Anat. & Phys. p. 7). Ihave beenable to investigate 
this bone say a very beautiful dicsetion skull, most kindly eommuni- 
cated tome by Professor Keferstein of Géttingen. | 
+ That this small intermediate bone, which effects the articular union 
“with the sqguama temporalis, is a portion of the incus was first made plain 
‘to me by a kind communication from my friend Flower, whom I induced 
to investigate this subject, and who wrote to me ‘that he had found ina 
young skull of Tachyglossus the incus, which had previously been entirely 
averlooked, and which would only subsequently be amalgamated with the 
malleus, but was then distinctly to be recognized. 
