264 
BULLETIN OF THE BUREAU OF FISHERIES 
Table 19 shows that the means of the dorsal-ray counts do not exhibit any general 
change throughout the range, as do the vertebrae, but appear to vary independently 
of geographical location. The nine principal localities are compared in Table 20. 
Out of 36 comparisons there are 16 that may be significant from a mathematical 
standpoint (see footnotes 1 and 2, Table 20). However, before considering these 
differences as valid we must know the amount of variability to be expected within 
any one locality. 
Table 20. — Comparisons of the means of the dorsal-ray counts of the principal localities 
Localities compared 
Puget Sound and Southeastern 
Alaska. 
Puget Sound and Yakutat 
Puget Sound and Prince William 
Sound 
Puget Sound and Dogfish Bay. 
Puget Sound and Kachemak Bay 
Puget Sound and Shuyak Strait 
Puget Sound and Old Harbor 
Puget Sound and Unalaska 
Southeastern Alaska and Yakutat 
Southeastern Alaska and Prince 
William Sound 
Southeastern Alaska and Dogfish 
Bay 
Southeastern Alaska and Kachemak 
Bay 
Southeastern Alaska and Shuyak 
Strait 
Southeastern Alaska and Old Harbor- 
Southeastern Alaska and Unalaska.. 
Yakutat and Prince William Sound.. 
Yakutat and Dogfish Bay 
Differ- 
ence 
between 
means 
Prob- 
able 
error of 
differ- 
ence 
Differ- 
ence 
divided 
by 
prob- 
able 
error of 
differ- 
ence 
Localities compared 
Differ- 
ence 
between 
means 
Prob- 
able 
error of 
differ- 
ence 
Differ- 
ence 
divided 
by 
prob- 
able 
error of 
differ- 
ence 
Yakutat and Kachemak Bay 
0. 66 
0.085 
i 7.8 
0. 06 
0. 045 
1.3 
Yakutat and Shuyak Strait 
.64 
.088 
> 7.3 
.63 
.093 
i 6.8 
Yakutat and Did Harbor ... .. 
.63 
.094 
‘ 5.2 
Yakutat and Unalaska 
.52 
.089 
> 5.8 
.08 
.046 
1.7 
Prince William Sound and Dogfish 
.32 
.063 
2 5.1 
Bay 
.24 
.048 
2 5.0 
.03 
.048 
.6 
Prince William Sound and Kache- 
.01 
.054 
O 
male Bay __ 
. 11 
.026 
2 4.2 
.00 
.063 
Prince William Sound and Shuyak 
. 11 
.056 
2.0 
Strait .... . . 
.09 
.035 
2.6 
.57 
.083 
1 6.9 
Prince William Sound and Old Har- 
bor ... 
.08 
.048 
1.7 
.02 
.019 
1. 1 
Prince William Sound and Unalaska. 
.03 
.038 
.8 
Dogfish Bay and Kachemak Bay 
.35 
.050 
2 7.0 
.26 
.047 
2 5. 5 
Dogfish Bay and Shuyak Strait 
.33 
.056 
2 5.9 
Dogfish Bay and Old Harbor 
.32 
.065 
2 4. 9 
.09 
.024 
2 3.8 
Dogfish Bay and Unalaska ... _ 
.21 
.057 
2 3. 7 
Kachemak Bay and Shuyak Strait.. _ 
.02 
.038 
.5 
.07 
.033 
2.1 
Kachemak Bay and Old Harbor.. 
.03 
.050 
.6 
.06 
.047 
1.3 
Kachemak Bay and Unalaska 
.14 
.040 
3.5 
.05 
.036 
1.4 
Shuyak Strait and Old Harbor. 
.01 
.056 
.2 
.55 
.083 
1 6.6 
Shuvak Strait and Unalaska _. 
. 12 
.047 
2. 6 
.31 
.094 
3.3 
Old Harbor and Unalaska 
. n 
.057 
1.9 
1 Of possible racial significance. 2 Of probable statistical significance. 
The maximum differences between the means of any two samples taken the 
same year in the same locality are shown in Table 21. In three localities the differ- 
ences between the means of the samples approach statistical significance (3.0 to 3.3 
times the probable error) the maximum difference being 0.28 ±0.084 or 3.3 probable 
errors. This would cast serious doubt on the significance of any difference not greater 
than 0.28, thus invalidating five of the differences in Table 20 that are valid from a 
mathematical standpoint. 
Table 21. — Maximum variations between the means of the dorsal-ray counts of any two samples taken 
the same year in the same locality 
[Asterisk indicates those approaching statistical significance] 
Locality 
Year 
sam- 
pled 
D iffer- 
ence be- 
tween 
means 
of two 
samples 
Prob- 
able er- 
ror of 
differ- 
ence 
Differ- 
ence di- 
vided by 
probable 
error of 
differ- 
ence 
Locality 
Year 
sam- 
pled 
Differ- 
ence be- 
tween 
means 
of two 
samples 
Prob- 
able er- 
ror of 
differ- 
ence 
Differ- 
ence di- 
vided 
by prob- 
able er- 
ror of 
differ- 
ence 
Craig. . ... 
Elrington Passage 
Maeleod Harbor. ._ 
McClure Bay 
1928 
1925 
/ 1927 
\ 1928 
1927 
0.21 
.28 
.25 
.06 
. 12 
0. 069 
.084 
.084 
.079 
.083 
*3.0 
*3.3 
*3.0 
.8 
1.4 
Kachemak Bay 
Shuyak Strait _ . 
Unalaska. 
1926 
f 1925 
\ 1926 
1928 
0.21 
. 17 
.21 
.28 
0.075 
.100 
.097 
.100 
2.8 
1.7 
2.2 
2.8 
