EASTMAN: SHARKS' TEETH AND CETACEAN BONES. 85 



therefore naturally arises, Are the cetacean remains associated with them on the 

 floor of the ocean, the bones of existing or extinct forms ? Of the resemblance of 

 the greater number of these bones, more especially the tympanic bullae, to exist- 

 ing genera, I have given a number of examples, and have occasionally had to point 

 out how closely some of them correspond with existing species, so that they may 

 be referred to them. But whilst these may be the bones of species still extant, 

 there are others which present greater difficulties in the identification, so that, like 

 the sharks, they may have belonged to animals which had lived in a previous 

 geological epoch. 



Neither the authority quoted, nor others who have occupied them- 

 selves with the study of Cetacean ear-bones, speak of having undertaken 

 comparisons between deep-sea and fossil material ; and although the 

 general anatomy and taxonomic characters of these organs are subjects 

 of great importance, and afford a promising field of inquiry, it cannot be 

 said that they have received the attention they deserve on the part of 

 either palaeontologists or cetologists. Insufficiency of material for com- 

 parison is of course largely responsible for this neglect : or if not actu- 

 ally insufficient, it is at least difficult to obtain a first-hand acquaintance 

 with the fossil supply, owing to its scattered distribution in New and 

 Old World museums. Another requisite involving some experience is 

 a nice perception of the degrees of difference or resemblance which fossil 

 and recent material offer on comparison with that dredged from the 

 ocean bottom. It thus appears that the subject is well hedged about 

 with difficulties. It is always advisable, however, to recognize the 

 natural limitations of whatever problem one may be engaged upon, and 

 to refrain from striving after greater accuracy than the nature of the 

 subject permits. 



In view of the circumstances just mentioned, we cannot attempt 

 more than a recapitulation of the principal characters of Cetacean ear- 

 bones, and an inquiry into the more general relations between Tertiary 

 species and those brought to light by the " Albatross " dredgings. Be- 

 fore entering upon this discussion it may not be inadvisable to give a 

 brief account of fossil ear-bones, and also to describe a single recent exam- 

 ple for the purpose of making our comparative observations more intelli- 

 gible. This procedure would seem to be necessary to an understanding 

 of various minutiae, the importance of which for systematic purposes has 

 been overlooked. We will consider these different points in order. 



Ear-bones of Fossil Cetaceans. 



Ear-bones of fossil whales appear to have been first recognized as such 

 by Baron J. von Hiipsch, an amateur collector of Cologne, who described 



