A RARE CRAB (P/RIMELA DENTICULATA) 183 
A RARE CRAB-PIRIVMELA DENTICULATA) IN 
ERE OH ORE 
By W. EDGAR EVANS, B.Sc. 
THE rocky coast in the vicinity of Canty Bay—three miles 
east of North Berwick, East Lothian—can provide, alike 
to marine zoologist and schoolboy, a hunting-ground as 
productive and as picturesque as any to be found on the 
shores of the Firth of Forth. Here the 6th Edinburgh 
Troop of Scouts spent a fortnight’s holiday in camp this 
summer (1921) and, as a result of the boys’ interest in 
their varied treasures, the rock-pools between tide-marks 
received a more than usually thorough investigation. 
On 2nd August, while examining the shore somewhat 
below half-tide level, and directly opposite the hamlet at 
Canty Bay, I obtained in a small, shallow  rock-pool, 
completely covered by a tangle of Fucus vesiculosus, a crab 
new to me; with it was a single young example of Hyas 
coarctatus. Before it could be brought home to the aquarium 
for study, captivity proved fatal. 
Reference to Bell’s “British Stalk-eyed Crustacea” 
convinced me that my capture was a female of Pzrimela 
denticulata (Montagu), and this identification has been 
confirmed by Dr James Ritchie of the Royal Scottish 
Museum, to which institution it has been presented. 
In life the colour of the carapace in the Canty Bay 
example was throughout a very dark purplish-brown, 
contrasting strongly with the pale straw-coloured limbs. 
Bell writes that the colour “in some specimens is greenish, 
in others purplish and brown mottled,” while Dr Ritchie 
informs me that in those he has seen from Plymouth, where 
it is not uncommonly dredged on clean, coarse, shelly gravel, 
there is generally a distinct trace of greenish mottling. He 
also refers to the marginal teeth of the carapace in the 
present specimen as somewhat broader at the base than 
