DEVELOPMENT AND LIFE-HISTORIES OF TELEOSTEAN FISHES. 821 
rock-pools of St Andrews in June and July, often hang in the water obliquely with their 
heads downward against the current. Their food at this time, when they measure 13 
inch to 1¥ inch in length, consists of copepods, larval cirripedes, sessile-eyed crustaceans 
(larval), small annelids, and Campontia, while the green cod, in addition to that food, 
feeds upon minute Mollusca, e.g., Homalogyra rotata, and various species of Ostracoda. 
The cod is less shy at this stage than the young green cod, and it is captured with less 
difficulty. 
Viewed from the dorsum they have a general pale olive-green colour. The sides 
are iridescent, with a pretty pinkish pearly lustre. The upper surface and sides of the 
head to a level with the eyes are studded with dark pigment. A regular series of dark 
pigment-spots runs along each side of the median dorsal line to the tip of the tail. 
About eight dark blotches occur on looking at the median lateral line, and as these are 
flanked by other dark patches in the upper lateral region, they give a very characteristic 
appearance to the fish (Pl. XVII. fig 8). This upper lateral region, just below the lateral 
line, shows behind the operculum nine dark spots. The first three are continued on the 
silvery belly, and then cease. The rest have connections with a series of median spots 
(five in number) in the middle line—bands, in several instances, passing from two upper 
spots to one lower median, or again bifurcating inferiorly. The ventral median line has 
on each side a band of pigment, continuous with the bars just described ; but the pig- 
ment-corpuscles are less distinct than along the dorsal lines, except opposite the base of 
the vertical fins, where the pigment is quite regular, and corresponds with the base of each 
ray. The first two dorsals have the blackish pigment towards the tip best developed on 
the membrane between the rays, the basal region being pale. The third dorsal has only 
a little black pigment. A trace of pigment also occurs towards the commencement of the 
anal fin. Blackish pigment is scattered on the sides and under surface of the mandible, 
and a thin dark streak passes backward in the middle line. The eyes are of a pale 
olive-green hue, with dark specks of pigment. The upper opercular region, and the 
surface above the cerebellum, are of a pale pinkish colour, due to the blood-vessels 
and the brain beneath. The vascularity of the latter seems to be considerable. The 
opercular region and the body are silvery. The pointed teeth are very evident in the 
jaws. 
The later stages have been dealt with in former papers, and need not be alluded 
to at present, except in regard to Ermur’s* notion that the markings in animals are 
primitively longitudinal. Now the young cod is conspicuously speckled in its earliest 
stage, and is rather pale and translucent in its next condition, the pigment which forms 
the transverse bars gradually grouping themselves on a somewhat pale surface, without a 
trace of longitudinal bands. In many other fishes, both round and flat (Pleuronectids), 
the same arrangement obtains, so that Haake had good grounds for demurring to this 
view from the study of the Australian fish Helotes scotus, which in the adult is marked 
by eight longitudinal bands, while young specimens have in addition a row of clear 
* Zoolog. Anzeiger., Viii., 1885, pp. 507-8. 
9: gery > PI 
