208 On the Gribble attacking a Submarine Cable. 
XX.—The Gribble (Limnoria lignorum, Rathke) attacking a 
Submarine Cable in New Zealand. By Cuas. CHILton, 
M.A., D.Sc., F.L.8S., Professor of Biology, Canterbury 
College, New Zealand. 
In 1904 (Ann. & Mag. Nat. Hist. ser. 8, vol. xiii. p. 380) I 
recorded the presence in New Zealand of the gribble (Limnorta 
lignorum, Rathke), which had been found attacking sub- 
merged timbers in Auckland, Lyttelton, and Akaroa harbours. 
The species has also been found at Cape Town in South 
Africa, at Sydney in Australia, and at the Falkland Islands, 
and has probably been unintentionally introduced in most 
parts of the world. 
In March 1916 Mr. Harold Hamilton, of the Dominion 
Museum, Wellington, forwarded to me a piece of the gutta- 
percha covering the inner core of the Cook Strait cable 
which had been burrowed into by some marine crustacean, 
together with three specimens of the animal. I found 
another still in the hole bored by it. On examining these, I 
found that they belonged to the species mentioned above, 
being distinguished from the indigenous New Zealand species 
L. segnis, Chilton, by the shape of the exopod of the maxiilli- 
peds and by the possession of a fairly well developed three- 
jointed palp to the mandibles. On further inquiry, I ascer- 
tained from Mr. Shrimpton, of the Telegraph Department, 
that the piece of cable examined came from a spot where 
a failure had occurred off Sinclair Head in Cook Strait at a 
depth of about 60 fathoms. The perforations that caused the 
sea-water to reach the inner core of the cable existed at a 
spot where a splice had been made, At other parts the 
armouring-wire of the cable prevents the animal from pene- 
trating to the inner core. This inner core was covered with 
a thin sheet of gutta-percha, and it was through this that the 
egribble was burrowing. 
While it is not astonishing that the gribble should be 
abundant in submerged timbers in harbours all over the 
world, having doubtless been introduced by old wooden ships, 
it is, perhaps, worthy of record that they have become so 
abundant that they attack the submarine cable at a depth of 
about 60 fathoms and at a distance of 12°75 nautical miles 
from the entrance to Wellington Harbour and of 4°75 nautical 
miles from the nearest land, Sinclair Head. It must be 
remembered also that in Limnoria lignorum, as in most Isopods, 
the eggs are carried in the ineubatory pouch under the body 
of the female until the young are hatched almost in the adult 
form, and that the animal is small and from its structure 
would not be expected to have much power of locomotion. 
