There is but one British species of Ligia, and this, the largest member of the whole tribe to be met with in these Islands,usually attains a length of two centimetres, while adult males may be nearly half as long again. It is the Oniscus oceanicus of Linnæus and lives on the sea shore, where it may be found at low tide beneath stones and rubbish in the crevices of timber. Ligia forms a connecting link between the woodlice proper and the many Isopods which actually live in the sea.
The colour of the animals is a greenish grey, and the compound eyes are almost black, so that they are very conspicuous; there are from eleven to fourteen joints to the flagellum of the outer antennae and this feature, taken in conjunction with the large size and habitat, is sufficient to identify the species in question.
On the coast of Essex the name "quay-lowders" is given to these crustaceans, "lowder" being apparently an old plural of louse.
It is worthy of mention that Mr. Webb, when in charge of the Marine Biological Station at Brightlingsea, examined a very large male specimen of Ligia oceanica, in which the maxillæ were duplicated and consisted of four pairs instead of two.
BRITISH LOCALITIES:—
England: Brightlingsea; (W.M.W.): Maldon; (W.M.W. from R.M.): Southend; (J.A.M.): Whitstable; (W.M.W.): Herne Bay; Margate; Dover; Folkestone; (J.A.M.)
Scotland: Shetland to Cornwall; (Norman, 49).
Ireland: East Coast; West Glengariff; Castletown; Berehaven; Bundoran; (Scharff, 63).
FOREIGN DISTRIBUTION:—
Europe: France; (25): Spain; (12): Denmark; Prussia; Norway; Faroe Islands; Belgium; (59).