Brachyura and Anomura of Puget Sound — Knudsen 
19 
its own eggs. Whether these were fertile or not 
is difficult to say as the eggs were extremely 
new. One male specimen contained algae frag- 
ments which resembled Ulva. While this species 
is all but impossible to observe in the field, 
many observations of feeding and other activi- 
ties have been made in the Point Defiance 
aquarium. Whenever barnacles are available 
this crab will feed almost exclusively on them, 
to the extent that it will ignore fresh-cut fish 
placed in the aquarium. In the public display 
rooms this crab often becomes a nuisance by 
continuously crushing barnacles and littering up 
the tanks with fragments of barnacle shells. 
REPRODUCTIVE ACTIVITY : Courtship and cop- 
ulation in this species is concurrent with the 
molting process of the female. The months of 
April, May, and June mark the peak of female 
molting and probably of copulation. On April 
14, 43 females were located at the Tacoma 
Narrows and many of these were in the process 
of courting or copulation. Again upon June 8, 
1 1 females of 69 encountered were in the process 
of courting. Six of the 11 females showed that 
the epimeral line was broken, indicating that 
ecdysis was soon to occur. In August, 10 females 
were collected at random and dissected to de- 
termine if sperm was in the spermatheca. Of 
the 10, 4 had full spermatheca, 2 had some 
sperm, and 4 had empty spermatheca. These few 
data suggest that copulation may occur any time 
during the late spring or summer, and that 
sperm is stored until the time of egg deposition 
in the late fall. Ovaries that were studied in 
May showed no evidence of oogenesis, though 
some were milky white in color. Dissections 
made in June showed 3 out of 5 specimens with 
ovaries 'whitish to clear, 1 with the ovary whitish 
in color and showing some development of the 
follicles, and 1 showing large yellow follicles. 
Of the 10 specimens dissected in August, 3 
showed considerable development of the ovaries, 
while 7 were underdeveloped. All specimens 
with developed ovaries had some sperm in the 
spermatheca, but not all animals with stored 
sperm showed ovary development. 
Fewer females were found in the field during 
the time of egg deposition and incubation than 
at other times in the year. Females with eggs 
were encountered during the last weeks of 
November. All females collected through the 
middle of February had eggs attached to the 
pleopods. However, the numbers of individuals 
of this species encountered were so small (the 
highest being 18 females with eggs out of 18 
encountered on January 26) that no graph will 
be presented. In April and in June an occasional 
female with eggs was encountered. These latter 
records were considered to be second-brood in- 
dividuals. 
In conclusion, it would seem that oogenesis 
occurs in the summer and fall, that egg deposi- 
tion begins in the last weeks of November, that 
eggs are carried until the middle of February 
when hatching is completed, and that hatching 
is followed by a period of quiescence, molting, 
and finally copulation, in that order. 
COPULATION: Our field observations of Can- 
cer oregonensis show that this species tends to 
court as other cancroid crabs do, and that the 
male carries the female about for several days 
prior to molting, then copulates with the female 
after she has completed the molting process. 
The male will continue to court or protect the 
female until her shell is hard enough for her to 
resume normal activity. This species may be 
more secretive than the larger species, Cancer 
productus, and hence observations of courting 
pairs moving freely about under water were 
not made. During periods of low tide, however, 
numerous courting pairs were found buried deep 
under rocks in little pockets surrounded by fine 
grained sand. The male assumes the normal 
superior position over the female and remains 
hidden during the courtship period. By carefully 
grasping the courting pair, it was possible to 
see the male with the pleopods inserted in the 
vulvae of the female. The very secretive be- 
havior of courting and copulating pairs, in 
contrast to C. productus, suggests that this spe- 
cies is unique in its courtship. Courting pairs 
found in barnacle masses high up on pilings 
remain well hidden between barnacles during 
courtship. In the laboratory courting pairs had 
less chance to hide themselves, but nevertheless 
burrowed down into the gravel substrate and 
remained as concealed as possible. 
PRODUCTIVITY: The eggs within the egg mas- 
ses of 17 C. oregonensis females were counted 
to determine their seasonal productivity. Sizes 
of the females varied from a carapace width 
of 17 mm to 26 mm, and the number of eggs 
