ray” 
of the Fishery Board for Scotland. 77 
for the males; the averages in the two months being for females 62°9 and 
90-1 mm., and for males 60°6 and 86°9. After August the growth does 
not appear to be rapid, the mean-size of the females of the group in October 
being on the 26th—for 100 specimens from 79 mm. to 108 mm.—95‘3 
mm., and on 31st (for eighty-six specimens from 80 to 111 mm.) 95:4 
mm. ; for the males the October averages are 89°2 mm, and 88'°0 mm. In 
winter, as might be expected from the habitat in this case, growth is 
slow, as may be seen by comparing the corresponding groups in October— 
December and March, April. 
In one or two instances two annual groups in the same series of 
measurements appear fairly complete, thus affording opportunity to 
deduce the amount of annual growth. Among the females on October 
31st the first series has a mean-size of 63:3 mm. (or about 23 inches), the 
range extending from 57 to 70 mm.; the second series, as stated, is 95-4 
mm., thus showing an annual increment of 32°1mm. Among the males 
the first series also ranges from 57 to 70 mm,, and has an average size of 
62°4 mm,; the second series, from 73 to 98 mm., has a mean-size of 88-0 
mm., showing an annual increment of 25°6 mm. In the December 
series, the average size of the males in the first group is 62°8 mm. and 
in the second group 87°6 mm., showing an annual increment of 24°8 
mm. Among the females the first group has an average of 62°3 mm., 
and the second group an average of 94:2 mm.; the annual increment 
indicated being 31°9 mm. 
Looking to these facts and the absence of the smaller forms in June, 
August, and the early part of September, the occurrence of one or 
two at the end of September, and the increase in their numbers later, 
T think there is little doubt that the first series represented in March is 
about one year old. And the phenomena presented by the ovarian eggs 
at different periods, and the measurements of the mature and immature 
fishes, as set forth above, make it probable that sexual maturity is not 
reached by the group until the second year, The largest specimen 
obtained, it may be added, the sex of which was not, however, 
ascertained, measured 156 mm. or 61 inches; it was from the Forth. 
The largest female determined was 136 mm. or 52 inches, and the largest 
male 141 mm. or 5,8, inches. They were both from the Solway. 
Contrary to what obtains among flat-fishes the males reach a size quite 
as large as the females, and presumably attain the same age. 
[ TABLES, 
