Artaur.—0On the Brown Trout introduced into Otago. 285 
transverse row, according to Günther, and the pyloric ceca fewer on an 
average by 9. As yet, I have made no examination of the number of 
vertebre, so my comparison in that and one or two other particulars is 
incomplete. 
With regard to the features of the head, as to structure, my remarks will 
refer to two heads, both of females—one of a fish, 4}1bs. in weight, taken 
in the Lee in October, 1877; and the other of a fish over Olbs. in 
weight, caught in the Upper Taieri River in March, 1878.  Fac-similes* 
of these are represented on pl. XIIL, fig. 1 and fig. 2 (S. fario) 
accompanying this paper. In fig. 1 the posterior end of maxillary is 2,% 
inches from the snout, and at its greatest width measures yy of an 
inch. The lower limb is strong and prominent, and the whole bone 
characteristically coarse and large.t Of the gill-covers, the posterior 
margin of the operculum forms nearly a right-angle with the june- 
tion line of the operculum and suboperculum. This junction or joint 
of the operculum and subopereulum forms an angle of nearly 23° 
with the axis of the body of the fish. The suboperculum in shape 
roughly resembles or approaches a rectangle, the posterior lower margin 
forming a blunt rounded angle. The average length, or middle length 
of this bone, is 1,3, inches, and the middle width $ of an inch. The 
interopereulum forms rather less than a right angle at its junction with the 
subopereulum, this line making with the axis of the body of the fish an 
angle of 47°. The lower margin is flatly rounded and continuous, nearly in 
line with lower margin of suboperculum, and the anterior extremity nearly 
semi-circular. The preoperculum is sinuously rounded in margin, and 
covers about one half of the surface of the interoperculum. 
In the case of fig. 2, the posterior end of maxillary measures 212 inches 
from the snout, and the body of the bone very nearly 4 an inch at its greatest 
width. It is approximately similar to the maxillary of fig. 1, the Lee 
Stream trout, only the posterior extremity is much more rounded, this fish 
being evidently an older individual. The end projects Q4 in. behind 
vertical, from posterior margin of orbit. The posterior margin of the 
operculum forms nearly a right-angle with the junction of the operculum 
and suboperculum. This line or joint of operculum aud suboperculum 
forms an angle with the axis of the body of the fish of nearly 26°. The 
suboperculum in shape roughly approaches a four-sided figure, almost a 
rectangle, the posterior lower margin forming a blunt angle with a sharp 
curve at the apex. The middle length of this bone is 147; inches, and its 
middle width $ inch. The interoperculum forms at its junction with the 
* [Reduced one-half from author's original drawings.] 
t It projects 45. in. behind the vertical, from posterior margin of orbit, 
