80 



much more nearly allied than the sardine and sprat, for the otoliths of the 

 latter fish are not more than half of the length of its aristocratic relative, 

 and much broader and rounder in proportion, placed with the smaller end 

 directed forwards. Those of the sardine are curiously suspended, like the 

 clapper of a bell. These are the smallest fishes the otoliths of which I 

 have endeavoured to extract. 



The salmouidce, (which takes its name from the king of fishes,) is a 

 rather large family even in Eritish waters, yet but two examples only, the 

 salmon and smelt, appear in our local shops. Their otoliths are not veiy 

 unlike one another, if one can fancy the naiTow end of that of the smelt 

 produced, as is that of the salmon. That of the smelt is a very pretty 

 object, in-egularly oval or leaf-shaped, with a deeply-knotched outline, 

 whilst the salmon may be said to have its otolith somewhat pistol-shaped. 

 It will have been noticed that in all the otoliths, the upper side is but little 

 curbed outward from a line cli'awn from end to end, whilst the other or 

 lower side always is more rounded, so that as in the herring or mackerel, a 

 fine point or tail is produced by this rounded edge, early approaching the 

 fissure, and thence proceeding nearly horizontally, but as drawn in the 

 plate, perpendicularly to the extremity. It is from the position which this 

 side first assumes when it projects outwards, that the main differences 

 between the otoliths of this grou]) aie most easily recognized. Thus in the 

 fresh-water herring or pollau, aln-.ost peculiar to Ireland, this rounded 

 side, although staiting below, rises slightly higher than the apex, the 

 sa'mon has the apex decidedly liigher, but exactly the contrary may be 

 observed in those of Cori/ffonuv. the snout-fish of Holland, a fish unknown 

 in the London markets, until the Dutch eel-boats brought specimens over 

 a few years ago. The otoliths of this fish are thick in proportion to its 

 size, but not so much so as those of the cat-fish, {Anarhichis liqnis) from 

 its immense mouth aud fonnidable teeth, sometimes known as the wolf- 

 fish, the otolitlis of which have some points in common with those of the 

 salmon, they are small in size, not exceeding two-tenths of an inch in 

 length. 



When we investigate the flat-fishes, we find another shape altogether • 

 From the natural habits of thtse fishes, we should not feel surprised if 

 one of the otoliths were Avantino altogether, or degraded to a minute 

 travesty of the other, but, as is well known, by a twist of the vei'tebra 

 where the neck joins the skull, the organs for both sight and hearing are 

 brought naturally into play, and there is no difference in the size of the 

 internal bones. Living almost entirely at the bottom of the water, 

 assimilating the surroundings in hue. and partly concealing themselves in 

 the sand, can they need to hear much, or at all ? and should we not expect 

 to find the otoliths like those of the herring and its allies, reduced to a 

 mere nothing '? 



But evolution will not assist us here at all. The otoliths are well 

 developed, and what is more, approach those of the majority of fresh- 

 water fishes in shape. 



