58 



Part III. — Twenty -fourth Annual Report 



The earstones of the mackerel are comparatively small. The one 

 represented by figure 36 is from a fish of average size and about 3*5mm. 

 in length. It has a general resemblance to the earstones of the herring, 

 being narrow, with the sides parallel, the posterior end obtusely rounded 

 and unequally bifurcated in front, the lower branch being produced into 

 a narrow- pointed extremity. 



Fam. GobiidjE. 

 Genus Gobius. 



Gobius niger, Linn. The Black Goby. PI. ii. b., figs. 19 and 20; pi. 

 v., fig. 6. 



In this species the earstones are large in proportion to the size of the 

 fish, and their broadly rhomboid form is so unlike that of the earstones 

 of any of the other kinds of fishes examined that they appear to be 

 characteristic of this particular species and to indicate that it might be 

 possible to identify the fish almost entirely by the earstones. 



The two fishes from which the earstones shown on PI. ii. b. were 

 obtained measured 105mm. in length, and their earstones are about 4mm. 

 long by tully 3mm. in width. These earstones are thus about equal to 

 one twenty- fifth part of the length of the fish. 



Gobius minutus, Gmel. The Speckled Goby. PI. ii. b., figs. 21-24. 



The largest of the four fishes represented by the earstones shown on 

 pi. ii. b., figs. 21 to 24, measured about 3 inches in length. The other 

 three were smaller, the largest being 54 and the smallest 43mm. The 

 earstones of the larger specimen were obscurely quagrangular in form and 

 measured about 2"2mm. across the longest side, the width being slightly 

 less. I he earstones of the other specimens were very small, and 

 resembled minute circular discs, the largest being little more than 1mm. 

 in diameter. 



Fam. Callionymid/E. 



Genus Callionymus. 



Callionymus lyra, Linn. The Dragonet. PI. iii. b., figs. 10-14; pi. 

 v., figs. 10 and 11. 



The earstones of the dragonet are very small, and they are subovate in 

 outline; the lower margin is nearly straight, but the upper is boldly 

 arcuate. The posterior end is rather blunt, but the anterior extremity 

 ends in most of the specimens in a short point. In some of them it is 

 slightly bifid, and the upper margin is also obscurely crenulated. 



The earstones of five fishes of different sizes are shown on plate iii. b. 

 The fishes measure 10 inches, 8 J inches, and 7| inches in length, while the 

 length of other two (figs. 13 and 14) is doubtful. The earstones of the 

 largest fish are about 3mm. long, which is equal to about one eighty- 

 fourth part of the entire length of the fish. The earstones of the others 

 are somewhat smaller and rather more pointed at the extremities. 



Callionymus maculatus, Bonap. The Spotted Dragonet. PI. iii. b., figs. 

 1-9; plate v., figs. 18 and 24. 



