DENNIS, ON CETACEAN BONES. 
195 
furnish other clear distinctions ; but it is_, perhaps^ too prema- 
ture, at present, to found any arguments upon them ; yet in 
the case of figs. 1 and 6, it may be seen, especially in the 
latter, that there is no correspondence with the whale. Fig. 1 
is taken from a flat fragment of bone which, if it belonged to 
the whale, must have been a rib. It diff'ers from that of the 
whale's rih as well in its fine and close-grained structure, as in 
the character of its Haversian tubes. The whale's rib appears 
to be made up of cancellous structure, while in the rib of the 
sperm-whale the Haversian tubes expand into the same sort 
of cavities, but I can detect very little diff"erence otherwise ; 
perhaps the canaliculi in the sperm whale are a trifle finer 
and more numerous than those of the Greenland whale. 
Fig. 1 represents a section of rolled Crag bone just adverted 
to ; and fig. 2, fossil elephant from the Drift ; and on the right, 
figs. 8 and 9, the jaw of the whale, recent, and the vertebra 
of the same, fossil : they are accurately engraved, so as to 
show the relative thickness and number of the canaliculi. 
Fig. 1, in its Haversian lacunae, shows the delicacy and dis- 
tinctness characteristic of Pachyderms ; and the free lacunae 
compare in all essentials likewise. The marvellous distinct- 
ness often exhibited in the fossil bone of the Drift elephant I 
have not met with in any Crag specimen; the canaliculi 
more or less are obliterated, but in those parts of the section 
where they are less so the correspondence is visible. Fig. 3 
gives, more highly magnified, the free lacunae of a Crag 
fossil and Drift elephant, taken from diff'erent specimens, but 
exhibiting the same characters ; and, in fig. 4, are seen the 
Haversian lacunae of Crag and Drift fossils compared together ; 
and on the opposite side of the plate (figs. 10 and 11) are 
shown the lacunae, free and Haversian, of the recent and 
fossil whale, magnified in a similar degree; by which the 
relative coarseness and numerical proportion of the canaliculi 
may be judged of, as well as their blurred appearance and 
their thickening at the ends, so very apparent both in the 
Greenland and sperm whales. In figs. 3 a, 4 a, representing 
lacunae of the Crag fossils, it will be seen that as much as 
they approach those of the fossil and recent elephant (figs. 3 6, 
4 b, and 12 a and b), so in an equal degree do they diff'er from 
those of the whale (figs. 10 and 11). I cannot distinguish 
any difi'erence in size between the canaliculi of fig. 4 a and 
fig. 4 bj though, from the more perfect condition of fig. 4 b, 
they appear more numerous. They appear finer and more 
numerous than those of fig. 14 a, which is elephant from the 
Gravel, as also they compared well with those of the recent 
elephant. Not having yet been able to procure the bone of 
