The leech was discovered when botanist Leonard Cockayne and Walter Dunlop (an analytical chemist from Orepuki) visited Taumaka, the largest of the Open Bay Islands, in February 1903. Dunlop was looking for wētā in muttonbird burrows when he was bitten on the wrist. As Benham put it, in his description of the new species, "Fortunately Mr Dunlop is keenly interested in natural history, and he carefully withdrew his hand and found a leech attached thereto”.
