366 MR. W. H. FLOWER ON THE OSTEOLOGY OF THE SPERM-WHALE, 
the former. The right bone is 10-2 in length in a straight line, the other half an inch 
shorter. They differ in many particulars from the same bones in the Cachalot. They 
have a single, strong, and tolerably uniform curve, are but slightly compressed, much 
thickest in the posterior half, and gradually tapering forwards, and, though presenting 
some well-marked longitudinal ridges, have no angular processes projecting from. the 
surface. The disparity in size between these bones and those of a perfectly adult female 
of H. rostratum in the Museum of the University of Oxford is extraordinary, the latter 
being but 5” in length, and very much more slender in proportion. As the male 
Hyperoodon does not exceed the female in bulk so much as the male Cachalot is said 
to do the opposite sex, we may expect to find fully as great a difference in the pelvic 
bones of the two sexes of this animal. In the Museum of the Royal College of Surgeons 
is a bone (No. 2460, Osteol. Series) presented by the late Dr. Buckland, and. described 
in the catalogue as “the left pelvic bone (ischium) of a Cachalot (Physeter macroce- 
phalus).” It may possibly have belonged to a female of this species, though it presents 
but little resemblance to those of the males above described, and, indeed, is more like 
that of the Hyperoodon. Its length is 8}”; its general form that of a club, being 
dilated towards one extremity, and much attenuated at the other. It is but slightly 
compressed, and has a single strongly marked curve. 
Conclusion. 
In the foregoing description of the skeleton of the Cachalot I have made but little 
comparison with animals of the genus Kogia, having in fact had no opportunity of doing 
so. ‘Lhe only two skeletons at present existing are both at Sydney, and-no adequate 
description of them has yet been published. From such indications as we have (further 
elucidated by some photographs kindly sent me by Dr. Bennett and Mr. Krefft), there 
can be no doubt that they belong to a genus which, both in external and osteological 
characters, is perfectly distinct from, though nearly allied to, Physeter. In the sketch 
of the classification of the Cetacea, appended to the description of the skeleton of 
Inia*, the genera Physeter and Kogia are united to form the subfamily Physeterine, 
which, with the Ziphiine (including Hyperoodon, Ziphius, &c.), form the very natural 
family Paysrrerip®. A detailed examination of every part of the skeleton of Physeter 
has perfectly corroborated the position then assigned to this genus. Materials are at 
present greatly wanted to complete our knowledge of the osteology of the Ziphiine ; 
hence it is impossible to say to which of the genera of that section Physeter approxi- 
mates most closely. 
After a concise and masterly analysis of the almost inextricably perplexed literature 
of the zoology of the Cachalots}, Cuvier came to the conclusion that, up to the time at 
which he wrote, but a single species could be considered to be truly known. Since then 
the claims of at least one distinct species to a place in the zoological system have been 
* Trans. Zool. Soe. vol. vi. p. 110, 1867. + ©Ossemens Fossiles,’ edit. 1836, vol. viii. p. 189. 
