THE Ministry of Agriculture and Fisheries has issued a notice (Fisheries Notice, No. 22, June 1934) on this crab, pointing out that it “would in no wise be a welcome addition to the British fauna”. During its migrations, particularly upstream, the crab tunnels into river banks and the wash of water in these burrows is liable to cause subsidence and hence serious damage to the banks. Further, the crab is voracious; it clears bait from lines and eats the fish-taken thereon, and bites through nets and lines. The note suggests that a careful watch should be kept for this crab, especially on the east coast of Great Britain; its destruction at all possible times might at least assist in restricting the numbers of this unwanted invader.