66 



of those of Fishes and Reptiles, and are liable to an early disappear- 

 ance from the jaws, tliey are lodged in deep alveoli, and are accom- 

 panied with a fixed condition of all the bones of the face as in 

 Gavials, Crocodiles and Alligators, in order to afford a stronger re- 

 sistance during the conflicts of these animals \vith living prey. 

 The great extension of the intermaxillary bones raises the nostrils 

 to tlie crovvn of the head, and enables the animals to breathe with- 

 out raising their large head above the \vater, or bending backwards 

 their very short neck. The extension backwards of their strong 

 upper jaw-bones over the cranial cavity, and the inclination up- 

 wards and forvvards of their flat oceipital bone from the horizontai 

 position of the head, pvoduce a remarkably compressed ridge across 

 xhe vertex of the skull, and inciine the occ\'p\iai\ Jornmen of the 

 Grampiis upwards and forvcards as in the above-nientioned Reptiles. 

 The parietal bones being throvvn to the iateral parts of the cranium, 

 and the frontai bone forming a narro\v band across the head, the 

 oceipital bonealmost touches the npper jaw bones along this trans- 

 verse ridge, and presents an extensive surface for the attachment 

 of the strong museles connecting the head to the spine. The coarse 

 fibrous and spongy texture of the bones, and the thickness of the 

 parietės of the cranium, are further analogies \vith Reptiles, and the 

 want of perforations in the ethmoid bone for olfactory nerves, shows 

 a deficiency of one important organ of sense. 



Dr. Grant adverted to the want of symmetry in the bones of the 

 head, \vhich is so remarkablc in the animals of this genus, and stated 

 that in examining lately the large collection of skeletons and škulis 

 of blowing Cetdcca in the Cabinet at Paris, he found scarcely 

 one which did not exhibit an increased developnient of the right 

 side of the head, frequently t\visting the nostrils so considerably 

 to the left side that the streams directed through the>:e passages 

 mušt have fallen at some distance from the bodj' of the animal. 

 The left side is gencrally less developed in Mammalia than the 

 right, and it appears to be the reverse in Birds, where the de- 

 velopment of the ovary and oviduct is ahvays checked on the right 

 side. Thcse pbac^^mena ma)' depend on the difFerent position of 

 the dcscending aorta in the two classcs, and its influence on the 

 nervous and other systems along its course. The unity of plan in 

 the developnient of the head of piscivorous Cetacea is remarkably 

 illustrated by the discovery of teeth in the louer jaw of ihe Jceius 

 of the toothless Balceiia. The whoIe proportions of the bones of 

 the head and trunk of the Grampus are massive and strong, and in- 

 dicate an animal possessed of great muscular strcngih, and a most 

 formidable antagc nist to the gigantic whales of the Arctic Seas. 



He observed that the feeble attaciiment of the slender jugal 

 bones and of the petrous and tympanic portions of the temporal 

 bones, generally causes them to disappear, as in the presert instance, 

 in maceratins; the škulis of Cetacea. But such donations as this 

 were most valuable to the Society, as objects of comparison both for 

 recent and extinctspecies of animals but little known and difficult of 

 access, and as specimens rarcly to be obtained by any other means. 



