DR. J. MURIE ON THE ORGANIZATION OF THE CAAING WHALE. 251 
wards and inwards, in the space betwixt exo- and basi-occipital, squamosal, and pterygoid 
bones. At the inner extremity it is slung, as it were, by a fibro-cartilaginous attach- 
ment from what appears as a hamular process of the pterygoid. Below this, and ante- 
riorly, is a broadish ligament which fastens it to the ali- and orbito-sphenoids. ‘To the 
commencement of the Eustachian tube it is connected by strong fibrous tissue, such as 
composes the canal itself; but there is besides, somewhat rearwards and inwards, a 
padding of cartilage. Behind this is a great vascular plexus reaching to the condyloid 
foramen. Between these and the tympanic fibroid tissues obtain. Posteriorly, exter- 
nally and at the narrow end of the bulla the broad strip of the stylo-hyal cartilage 
arises from the exoccipital, and here is so imbedded as to prevent the tympanic im- 
pinging upon the latter bone. ‘The facial nerve escapes from the skull by a separate 
foramen immediately in front of the cartilage; and the auditory tube ends in the recess 
and tympanic membrane hard by. In the dried skull of this species the petrotympanic 
bones are all but quite loose; the fibro-cartilaginous parts, above described, therefore 
act as cushions around them. But, moreover, the vascular network and oily and fatty 
substances hereafter described supply a soft external casing supplementary to audition. 
The Eustachian canal, as it leaves the tympanic bulla, has considerable diameter, and 
retains it more or less uniform as it passes forwards towards the fauces. A tough 
membrane and rete mirabile lie superficial to it. 
5. The Tongue.—This is a fleshy organ, dorsally covered by a thick corium or leathery- 
like envelope. It is perfectly smooth, and superficially flat, excepting at the root. 
There it exhibits numerous glandular papille and depressions, probably the representa- 
tives of papillz fungiformes; other larger and much deeper furrows behind may be 
either circumyallate cavities or simply mucus-glands. The glosso-pharyngeal ruge 
are narrow, linear, and longitudinal. 
The tongue’s length is 7} inches as it lies in the recumbent posture; posteriorly it is 
4 inches across, narrowing regularly to the tip. About a couple of inches of the apex 
is free ; and there is a considerable fold of loose membrane beneath, forming a distinctly 
marked frenum lingue. ‘This is flesh-coloured, with nearly black outer edges. The 
tongue, however, is apparently not capable of protrusion beyond the mouth. The 
sublingual membrane is thrown into crescentic folds only moderately raised; and these 
interdigitate the one with the other, whilst the freenum itself connects these by rather 
irregular, crenate, transverse plice. 
I may as well at once refer to several of the fleshy masses of the submandibular 
region and composing the lingual organ itself. Among these the most conspicuous 
superficial layer, to wit, the mylo-hyoid, is of great breadth, moderate thickness, and 
coarse in fibre. The two muscles together spread out from the lower jaws to the hyoid, 
and have throughout transverse fibres. It acts as a compressor of the inframaxillar 
pouch in the Piked Whale’. What may be the homologue of a digastric is a relatively 
’ Phil. Trans. 1868, p. 220. ’ 
VOL. Vill.—Part iv. February, 1873. 20 
