of the Fishery Board for Scotland. 



65 



Gadus merlangus, Linn. The Whiting. PI. ii. a., figs. 6-8, 30 and 31. 



The earstones of numerous whitings have been examined, and all, 

 except those of very small specimens, agree in the peculiar form by which 

 they may be distinguished from other species of Gadus. They are 

 elongated and narrow. The lower margin is tolerably even and slightly 

 convex. The anterior end is obliquely truncated, and with the edge 

 usually crenulate. The upper margin, for about two-thirds of its length, 

 from the anterior extremity, is nearly straight and parallel with the lower 

 edge, then it gradually converges towards the lower margin, so that the 

 posterior end is narrow and tapering and has a sharp-pointed termination. 

 The earstones are somewhat concave outwardly, and slightly convex and 

 nearly smooth on the inside. The lower edge is tolerably thick, while 

 the upper, especially where it begins to taper towards the posterior end, 

 is compressed and thin. 



Photographs are given of the earstones of five whitings which measured 

 respectively 14 inches, 12| inches, 11| inches, 11 1 inches, and 9 inches in 

 extreme length, and the size of their earstones given in the same order is as 

 follows : — 20mm. long by 5mm. in greatest width (fig. 30), 16mm. by 

 about 4 5mm. (fig. 8), 16 '5mm. by nearly 5mm. (fig. 7), 15mm. by about 

 4'7mm. (fig. 6), and 12'5mm. by about 4mm. (fig. 31). The earstones of 

 two young whitings, about 68mm. (2f inches) in length, but which are 

 not represented among those photographed, measured 3*5mm. by about 

 r5mm., which is fully twice the length of those of a lumpsucker 15 J 

 inches long. 



By comparing the length of the earstones of a number of whiting of 

 average size with the length of the fish they were taken from I found 

 that, though the proportion varied to some extent, the length of the 

 earstones approximated to about one-eighteenth part of the extreme 

 length of the fish. 



The proportion between the length of the earstones and of the fish 

 they belong to varies considerably in the different kinds of fish. An 

 examination of numerous examples of fish belonging to various species 

 seems also to indicate that where the earstones are massive in structure, 

 as in some of the Gadoids, they are shorter in proportion to the length of 

 the fish than those that are thin and narrow. This may tend to explain 

 why the earstones of the whiting are generally proportionally more 

 elongated than those of the haddock or codfish. 



Gadus virens, Linn. The Saithe or Coal-fish. PI. i. a., figs. 14-16. 



The earstones of large coal-fish are very massive in structure. Fig. 14 

 represents those of a fish of average size, but I am unable to state the 

 exact length of the fish, though it could not be much under 36 inches. 

 These earstones measure about 24mm. long by about 8mm. in greatest 

 width. The upper and lower margins are tolerably straight and nearly 

 parallel, and they are slightly crenulated along the edges. The front end 

 is somewhat obliquely truncated, but at the posterior end the upper and 

 lower margins converge so that they meet and terminate in a blunt point. 

 They are also slightly twisted, and have the outer side incurved and 

 slightly rugose, while the inner side is convex and nearly smooth. 



Figs. 15 and 16 represent the earstones of two saithe about 15 inches 

 long ; they are narrow and elongated, and small when compared with 

 those of the whiting. These earstones measure from 11mm. to about 

 ir5mm. in length, which is equal to about the one thirty-third part of 



E 



