340 
SCANDINAVIAN FISHES. 
Mugil cephalus, p. p., Lin., By si. Nat., ed. X, tom. I, p. 316. 
Mugil capita, Cuv., Regn. Anim., ed. 2, tom. II, p. 232; 
Bonap., Fn. Ital. Pesci, lab. No. 92; Cuv., Val., Hist. Nat. 
Poiss., vol. XI, p. 36, tab. 308; Kr0y., Danin. Fiske, vol. I, 
p. 300; Gthr, Cat. Brit. Mus., Fish., vol. Ill, p. 439; 
Steind., Stzber. Akad. Wiss. Wien, Math. Naturw. Cl . , LVII, I 
(1868), p. 680; Coll., Forli. Vid. Selsk. Christ. 1879, No. 1, 
p. 60; Mor., Hist. Nat. Poiss. Fr., tom. Ill, p. 188; Day, 
Fish. Gt. Brit., Irel., vol. I, p. 230, tab. XLVI; Lill.j., 
Sv., Norg. Fisk., vol. I, p. 408. 
This species perhaps attains the same size as the 
Thick-lipped Gray Mullet, and is just as little distin- 
guished from it by any striking difference in form or 
colour, as the preceding species. The most distinct 
characteristic of the Gray Mullet is that, among the 
Scandinavian species of this genus, it has been arrested 
at the lowest stage in the common course of develop- 
ment. This development, although it does not seem 
to have started immediately from the Mediterranean 
Mugil ceglialus , distinctly points to an original form 
that essentially corresponded to it, both in the com- 
paratively great length of the head — more than x / 2 
the distance between the first dorsal fin and the tip of 
the snout — and in the even, arched palate, not yet 
furnished with lateral ridges like the roof of the pha- 
rynx, but, on the other hand, with papillae, partly 
hardened into teeth, on the lateral parts. We have 
endeavoured to show the remaining characteristics of 
this original form in the appended table of averages, 
based on four specimens, from 196 to 363 mm. long, 
of Mugil capito, three, from 251 to 455 mm. long, of 
Mugil auratus, and six, from 267 to 452 mm. long, ol 
Mugil chelo. In this table are also inserted the changes 
of growth that have appeared in the last-mentioned 
species in the respects under consideration. 
Average in the case of 
Mugil 
capito. 
Mugil 
auratus. 
Mugil 
chelo. 
Length of the body expressed in millimetres . 
267 
337 
271 
363 
1 
Length of the head in % of that of the body _ 
22.8. 
21.2 
20.9 
20.6 
9 
., ,, ., ., behind the eyes „ ,, ,, ,. „ „ „ _ 
13.s 
12.r 
11.0 
10.9 
3 
., ,, ,, ,, ,, „ ,, the distance between the first dorsal fin and the tip of the snout 
51.9 
48.2 
,46.9 
46.5 
4 
behind the eyes .. „ .. ,, „ ,, .. ., 
30.9 
27.5 
24.9 
24.7 
5 
Breadth of the mouth in % of the length of the head _ 
31.4 
32.6 
35.o 
35.6 
6 
Least breadth of the interorbital space in % of the length of the head behind the eves 
70.s 
75.9 
82.9 
86.8 
7 
Length of the snout ,, ,, ., .. ,, ,, ., .. ., ., ,, 
49.3 
51.i 
60.9 
8 
,, ., ,, lower jaw ,, ,, „ ,, ,, ., ,, ., .. ., ., 
52.8 
63.o 
64.4 
9 
Least depth of the tail , ., ,, ., ., „ ., .. ., . 
68.8 
70.8 
88.6 
88.9 
10 
Length of the base of the anal fin in % of the least depth of the tail 
112.9 
106.9 
97.9 
95.9 
11 
Height of the upper lip in % of the length of the head 
5.8 
6.7 
10.5 
9.8 
12 
„ ,, ,, ., ,, ,, „ „ ., ,, behind the eyes 
9.9 
11.8 
19.6 
18.6 
13 
,, „ ,, ., „ ,, ,, „ ,, ,, ,, snout 
20. o 
23.o 
32.5 
30.7 
14 
,, ,. ., ,, ,, ., ,, ,. ., .. ., lower jaw 
18.8 
21.6 
31.2 
29.i 
15 
,, ,, ,, ,. ., ,, ,, ,, ., breadth of the mouth... _. 
18.7 
20.7 
29.9 
28.0 
16 
Length of the base of the second dorsal fin in % of the leDgth of the head behind the eyes 
55.3 
67.2 
73.8 
71.4 
17 
Length of the pectoral fins in % of the length of the body 
14.6 
17.o 
15.4 
15.3 
18 
., ., „ „ ,, ,, „ ., the distance between the ventral fins and the tip of the snout 
42.9 
50. 5 
45.3 
46.i 
19 
,, „ „ ventral ., ,, ,, the length of the pectoral fins 
86.s 
64,5 
80. o 
76.7 
20 
Least depth of the tail ,, ,, „ „ „ „ „ „ „ 
63.5 
50.5 
64.i 
63.5 
In all the first ten of the above relations the series 
advances in the same direction, and is followed by the 
changes of growth in Mugil chelo. A comparison be- 
tween the first and the third columns, in which the 
length of the body is almost the same, shows the dis- 
tinctive characteristics of Mugil capito, as well as 
of the supposed origin which may have been the 
starting-point of the common development. The next 
five relations (11 to 15 inclusive) show the most dis- 
tinctive character of Mugil chelo; but it is singular that 
here the changes .ol’ growth in this species • — as though 
it underwent a retrograde development — run in the 
opposite direction to the form-series, which, on the 
other hand, follows the direction of the changes of 
