62 Part IIT.—Twenty-fourth Annual Report 
long and upwards, differ in shape froim the earstones of other species of 
Gadus in being distinctly wider at the anterior end, instead of having the 
upper and lower margins parallel or nearly so. The lower edge, which is 
longer than the upper, is only slightly convex, and in some cases nearly 
straight. A thick rib extends along the lower aspect of the convex 
or inner side, as indicated by the photographs (fig. 2), but the stones 
become thinner towards the upper edge. The upper edge is slightly con- 
vex and shorter than the lower. Anterior end obliquely truncated. 
Posterior end narrow, bluntly rounded, and terminating in a shallow 
depression. Upper and lower margins usually irregularly but distinctly 
crenulated. The pair of earstones represented on the plate by fig. 1 were 
removed from a codfish 402 inches long; they measure about 21mm. in 
length by fully 10mm. in depth.* Figure 2 on the same plate represents the 
earstones of another fish 362 inches long, which measure about 18mm. by 
fully 9mm. Below I give in tabular form the sizes of the earstones of © 
other fishes represented on pl. i. A. 
Earstones. 
Figures on Plote | Tength of Fish. 
Length. Depth. + 
3 15 inches, About 13‘0mm. Nearly 6‘0mm. 
4 2ie) AS; », 155mm. 7'5mm. 
5 21 fe 4eomim: About 6'5mm. 
6 10 ae 5 L0:5mm: Ae 40mm. 
7 9 5 >,  9'5mm. i 3°7mm. 
8 De ee ee Gramm: 3 25mm. 
9 43, ny Tpanhany as 2-3mm. 
10 ad 55 55). DG ieaT a. Fully 20mm. 
Gadus eglefinus, Linn. The Haddock. PI. il. ., figs. 1-5 and 9-16 ; 
pl. iv., figs. 1 and 2. 
The earstones of tolerably large specimens of haddock have the upper 
margin nearly straight, and parallel with the lower margin; the crenula- 
tion of this margin is uot very strongly marked, but the lower margin, 
which is slightly convex, is distinctly crenated. Among the haddocks 
examined for the purposes of this paper, one was thin and emaciated, and 
its earstones were not only comparatively narrow and elongated, but they 
were also devoid to a considerable extent of the grooves and ridges so 
characteristic of earstunes of the normal type; this pair of earstones is 
represented by fig. 3., pl., il. a. 
A fairly large number of haddocks have been examined, and I find that 
most of those about 8 or 9 inches long have their earstones obliquely 
truncated in front, and that posteriorly the upper and lower margins con- 
verge, though somewhat unequally, to form a narrow, blunt pointed 
extremity. They are also laterally incurved, so that the hollow surface is 
toward the outside, the convex side being inside, as in those of the codfish. 
The earstones of the smaller haddocks are not so distinctly truncated in 
front, and the upper and lower margins are not parallel, but converge from 
the widest part near the anterior end gradually to the posterior extremity. 
* These earstones are thus equal to about the one forty-ninth part of the entire length 
of the fish. In the other example specially referred to they are about the one fifty-first 
part of its length. The earstones appear to be proportionally longer in the smaller fish. 
