164 MK. E. T. niGGINS OS THE OTOLITES OF FISH. 



tertiary formations when no other vestige of the fish to which they 

 belonged has been preserved, all the other remains consisting of 

 teeth and vertebrae of cartilaginous fish. It may be aB well to state 

 that, so far as my examinations of British fish have gone, every 

 species, recognized as such by Mr. Couch, has its distinction 

 borne out by the otolites. 



Much diversity of opinion exists as to whether the otolites are 

 to be looked upon as the " analogues " or "homologues " of the 

 ossicula aiiditns ; but it appears to me that their position in the 

 vestibular sac and semicircular canals proves that they are only 

 excessive development of the otocones, and not representatives of 

 the true ear-bones, — an opinion in which I believe most anato- 

 mists will concur. 



In a short notice published some years since, I stated that the 

 specific characters of the otolites Avere more to be depended upon 

 than the generic. Further investigations induce me to consider- 

 ably modify this assertion ; and altliough every species may be 

 recognized by its own peculiar central otolite, I am inclined to 

 believe that it is possible to group the species of each genus as 

 having some character in common. 



Possil otolites liave long been known to all collectors of tertiary 

 fossils, but no classification of them has yet been made. The first 

 attempt w^as that of Mr. Charlesworth, nearly thirty years since, 

 and engravings were made of some of the principal forms ;' but I 

 believe nothing further has been done with them. The formations 

 Avhich have yielded them in the greatest abundance are the Crag 

 (Coralline Crag), the Hordwell Highcliff, Bracklesham, Brook, 

 and Bramshaw tertiary-beds, and the Grault of Tolkestone. 



All the otolites from the Coralline Crag, that I have yet had 

 an opportunity of examining, belong, Avithout a single exception, 

 to existing species of Gadoids, viz. Cod, Whiting, Pollack, Wliiting 

 Pout, Grreen Cod, &c. ; there is therefore every reason for believing 

 that the portion of a skeleton of a fish from the Coralline Crag, de- 

 scribed in the ' Greologist,' and with some hesitation referred to 

 this famil}"", was undoubtedly Gadoid. 



Sufficient has been said, I think, to prove that, to the Palseon- 

 toloffist, the careful examination of these small bodies will be of 

 great assistance in enabling him to trace to a comparatively remote 

 era the first appearance of many of the existing species of fish. 



To the student of recent ichthyology they will be found of equal 

 value, enabling him to discriminate between closely allied forma. 

 I speak with tolerable confidence of their specific value, having 



