f 
July 22, IS 41 
- rx\ t 7 . f, ■ . .c. . 
Mr. E. W. Harrison 
2725 Monti ake Boulevard 
Seattle, Washington 
Dear Roger; 
I ara getting off those measurement sheets that I promised 
you in my last letter today or tomorrow without fail. 
With each of the envelopes containing the sheets on which 
our measurements were entered, except the second (II), are some 
averages ascertained by Hiss McCain while I was south last spring. 
They are figures that may be of some interest to you and which should 
appear somewhere in the report. They were compiled with an adding 
machine here and should be correct and reliable. 
Since Pat is not at hand, Wallace may need a word or two 
of explanation on some of the things that appear on these measurement 
sheets. Thinking that the barnacles might hold some clue as to the 
frequency of moulting, I often measured the largest barnacle found on 
the carapace of a crab, the measurement given being the approximate 
or average diameter of the barnacle. The largest white circular 
bryozoan was also measured. In most places I have "B*. . for the 
barnacle measurement and ”Bry*». . *” for the bryozoan measurement. 
Then., the little worms in circular calcareous tubes we listed as 
to' 
Spirorb- 4 s. 
rt w n wi it i ' 
In the first envelope a few sheets are clipped together. On 
those are some weights of eggs that Pat ascertained. We noticed quite 
a discrepancy in the right and left legs of the females, and so occasion- 
ally we measured the third leg of both sides, thinking that some time 
that asymmetry might be looked into. 
At the bottoms of the sheets arc the measurements of the 
large chela. 1 1 ook these because Weymouth at Stanford found that the 
most significant changes appeared in the claws and apparently vrare more 
indicative of the arrival of sexual maturity in a crab than any one 
other character. Unless you want to make use of these chela measure- 
ments in your report, they could be left for some future study. Wallace 
is perfectly welcome to them and may find them more significant than 
the actual widths and lengths of the oarapaoe. It might pay him to 
try them out on a curve if he has the time for it. 
