BARBADOS-ANTIGUA EXPEDITION 181 
chelz were mottled with white on a red background, and finely 
haired. The ‘‘finger’’ was very short and stout, and curved 
like a parrot’s beak, and the tips of the chele were crossed 
when closed like the mandibles of the cross-bill. Another was 
very conspicuously colored, being bright blue and dark red with 
antenne ringed with red and white. This is the form before 
mentioned that lurked under the tentacles of an anemone. I 
became aware of its presence when trying to detach an ane- 
mone from a stone, when I received several rather sharp thumps 
on the end of my finger causing a quick withdrawal of the hand. 
The sensation was most peculiar, somewhat like receiving an 
unexpected electric shock. Upon further examination and ex- 
periment, I found that these peculiar thumps were due to blows 
from the large chela of this pistol crab, which were being pro- 
jected forcibly forward, hitting my finger-tip with the end of 
the closed chela. At the same time the animal recoiled, but it 
would not leave the vicinity of the anemone, which, by the way, 
was armed by unusually large nematocysts and had conspicu- 
ously annulated tentacles. It occurred to me that the unusual 
color of the antenne of the crab, annulated red and white, was 
for the purpose of simulating the appearance of the tentacles 
of the anemone, thus forming a very good example of protective 
mimicry. Miss Van Wagenen tells me that she had a similar 
experience with the same species of crab and anemone. Al- 
though I have seen several cases in which there was a commen- 
sal relationship between brachyuran crabs and anemones, this 
is the first time I have found a macruran involved. 
Several species of mantis shrimps alled to Squilla were 
found. One, Gonodactylus wrstedu, was small and had a beau- 
tifully ciliated antenna-squame, as well as the pleura of the ab- 
dominal segments. The carapace and dorsal surface of the ab- 
domen were ornamented with fine round black dots. A bright 
reddish shrimp-like crustacean was carrying a surprisingly large 
mass of bright red ova and its eyes were covered by a transparent 
seale-like projection from the carapace. Why the ova should be 
so brilliantly colored in so many crustaceans is more than I ean 
explain. Perhaps in this case it is to match the color of the bearer. 
Another small macruran is quite robust in form, its head having 
a lateral profile reminding one of a miniature pig. The carapace 
