54 



P((rt III. — Twenty-fourth Annual Report 



Four specimens of the fresh- water perch were examined — one about 

 14 inches long, one 8 inches, one 7 inches, and one 6 .J inches. The 

 earstones of the largest specimen measured 10 -5mm. in length and about 

 5* 5 mm at the widest part, while those of the other three specimens 

 measured respectively 7mm. by 3-5mm. and 6mm. by 3mm. The larger 

 earstones are thus proportionally the shorter ones, the first being equal to 

 about one thirty-fourth part of the entire length of the fish, the next 

 about the one-thirtieth, and the last rather longer. These earstones are 

 very irregular in outline, and the greatest width is towards the posterior 

 end. The lower margin is tolerably even and slightly arcuate, but the 

 upper is irregular, with a prominent notch near the proximal end ; this 

 end is narrow and bluntly rounded. Both the posterior end and the 

 upper margin are distinctly but irregularly crenulate ; they are also 

 moderately compressed and thin. The earstones of the smaller fishes 

 have a general resemblance to those of the large one, but they are 

 distinctly less crenulated, and the surface is not so rugose. The specimens 

 seem to vary to some extent in form and sculpture. 



Fam. MuLLiDiE. 

 Genus Mullus. 



Mullus barbatus, Linn. Surmullet or Red Mullet. PI. iii. b., fig. 49 ; 

 pi. v., fig. 23. 



The fish from which the earstones were taken measured scarcely 8| 

 inches in length. The earstones are broadly ovate in outline, the posterior 

 extremity is truncated, while the proximal end is narrow and bluntly 

 rounded ; the lateral margins are obscurely crenulate, and the surface is 

 somewhat rugose. The earstones of the red mullet are apparently pro- 

 portionally smaller than those of the fresh-water perch. Those just 

 described measured only about 4* 5mm. long by about 3mm. in greatest 

 width, and are thus about equal to little more than one- fiftieth part of the 

 length of the fish. 



Fam. Sparid^e. 

 Genus Sparus. 



Sparus (Pagellus) centrodontus, De la Koche. Sea Bream. PI. ii. b., 

 figs. 6 and 7. 



The earstones of two examples of this species are shown on Plate ii. b. 

 The larger of the two fishes measured 17 inches in length, and the 

 smaller 15 inches. The earstones of the first (fig. 6) measured 15*5 mm. 

 along their greatest length, and 8mm. in depth, and those of the smaller 

 one (fig. 7) 14mm. by 7 '5mm. In their outline and markings these 

 earstones are somewhat similar to those of the large fresh-water perch, 

 but the lower margin is rather more arcuate, and they are more incurved 

 when seen from above. They are also considerably larger in proportion 

 to the length of the fish, being about one twenty-seventh or twenty- 

 eighth part of the extreme length. 



Fam. Scorp^enid^. 

 Genus Sebastes. 



Sebastes norvegicus (Ascan.). Norway Haddock. PI. iii., b., figs. 50-52. 



The earstones of three small examples of Sebastes are represented on 

 Plate iii. b. The fishes measured 5 inches, 5| inches, and 6 iuches in 



