138 Part ITT.—Twenty-fourth Annual Report 
The Caudal Fin of luscus has its hind margin slightly concave, that 
of minuzus is distinctly concave, aud in esmarkit the hind margin is 
deeply cleft. 
The ventral fin ends in a filamentous tip in all three species. 
The Mandible projects a little in front of the upper jaw in esmarkit; 
in minutus and luscus the upper jaw projects in front of the lower. 
The side and tip of the lower jaw are dar« coloured in esmarkii. The 
under-surface of the dentary part of the lower jaw is white in /uscus; pale, 
colourless in minutus. In consequence, the sensory pits on the under- 
surface of the dentary show up well in /uscws and are faint in minutus. 
The Barbel is long and stout in luscus and minutus. In esmarkii it is 
thin and short, not being longer than half the diameter of the eye. In 
the last species the barbel often lies back along the under surface of the 
lower jaw in the hollow between the two dentaries. The barbel is not 
so short in esmarkit as it is in Gadus virens, in which species it is very 
inconspicuous. 
The Lateral Line is curved over the abdomen in all three species. In 
luscus and esmarkii the line is dark and more prominent than in minutus. 
The bend rises from the hind straight portion more abruptly in duscus; in 
minutus and esmarkit the rise is more gradual. 
The Anus is beneath the beginning of the first dorsal fin in Juscus, and 
beneath the second half of the corresponding fin in minutus and esmarku. 
The Eye in the three species here discussed is specially large. In 
luscus it is slightly smaller than in minutus and esmarkii. The diameter 
of the eye is equal to or greater than the length of the snout, 7.e., the 
distance from the tip of the upper jaw to the anterior edge of the orbit. 
They all exhibit at times the loose cornea which is sometimes inflated 
with gas or fluid, giving the eye the well-known bulged appearance. 
Sometimes cysts are found on the front of the eyeball in the region of 
the iris. 
Two of the larger esmarkti, measuring 18‘5cm. and 19cm. in length, 
had eyes which appeared to be larger in proportion than the smaller fishes. 
The eyes measured in horizontal diameter 7°3 and 7°8 per cent. of the 
total length of the fish respectively. Four others measuring 19cm., and 
one of 2lem., had eyes measuring 7 per cent. of the total length of 
the fish. The small difference in diameter will, of course, entail a con- 
siderable difference in the area of the eye, and it is by the area, not the 
diameter, that the eye of the observer makes the comparison, Any 
variation towards an increase in the size of an already specially large 
character will of necessity attract attention. 
The barbel in duscus is rather bigger and stouter than that of manutus. 
In five specimens of the latter the barbel measured two-thirds or a little 
more than the horizontal diameter of the orbit. 
In the key are introduced the following Gadid species—G. callarias, 
G. virens, G. pollachius, G. luscus, G. minutus, and G* esmarktt. 
KEY, 
1. Lowrr Jaw (Length of)— 
a. projects in tront of Upper Jaw, . . virens ; pollachius ; esmarki. 
b. of same length as af 7 . virens (young) ; minutus (sometimes). 
c. shorter than ie Oe es : callarias; luscus ; minutus. 
II. Anus (Position of) — 
a. below the beginning of the First Dorsal Fin, . 5 . luscus. 
Due geese ae hrab alien ens. ee f “3 . pollachius ; minutus. 
Ca OG 2 Besgecond We Fai oy. CAE 3 5 minutus; virens; esmarkit. 
ad, 5 frst half 9351; Second ae, 5 ‘ ; callarias. 
