DK. J. MURIE ON THE OEGANIZATION 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 skuU 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 di-ied skull of this species the petrotympanic 

 bones are all but quite loose ; the fibro-cartilagmous 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 mii'abile lie superficial to it. 



5. The Tongue. — This is a fleshy organ, dorsally covered by a thick corium or leatheiy- 

 like envelope. It is perfectly smooth, and superficially flat, excepting at the root. 

 There it exhibits numerous glandular papillte and depressions, probably the representa- 

 tives of papillae fungiformes ; other larger and much deeper furrows behind may be 

 either circumvallate cavities or simply mucus-glands. The glosso-pharyngeal rugae 

 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 niches of the apex 

 is free ; and there is a considerable fold of loose membrane beneath, forming a distinctly 

 marked frsenum linguse. 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 fraenum itself connects these by rather 

 irregular, crenate, transverse plicae. 



1 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. TraM. 1868, p. 220. 



VOL. VIII. — PAKT IV. February, 1873. 2 o 



