278 = Dr. W.C. M‘Intosh on the Boring of certain Annelids. 
as well as elsewhere, such as several of the Spiontde, Eunice, 
Lysidice, Trophonia, Syllis armillaris, Psamathe fusca, Cas- 
talia punctata, Kulalia, Thelepus (Venusia), and Aphlebina. 
Of these, Lyszdice is often found under the calcareous spread- 
ing base of Corallina officinalis along with Leucodore, under 
the large littoral Ascidians at Herm, and in masses of Celle- 
pora from the deep water off St. Martin’s Point, Guernsey, 
and, though it would seem to take possession of an old tunnel, 
yet appears capable of accommodating the hole to its own 
wants. Lastly, a few Annelids bore rocks, stones, and shells 
of various kinds, amongst which are Leucodore, Dodecaceria, 
Sabella saxicava, Heterocirrus saxicola, Grube* (a species 1 
cannot at present distinguish from Dodecaceria concharum), 
besides some of the adjoining group, Gephyrea. 
There is no more common Annelid along the rocky parts of 
the beach at St. Andrew’s than Leucodore ciliata (Pl. XVIII. 
fig. 1); and,indeed,it is a very abundant British form in general. 
It especially haunts the soft blue shale at the West and Castle 
Rocks of the ancient city, apparently, like its companion Pho- 
las crispata, because it finds such more easily excavated than 
the denser sandstone, just as we see it avoiding the hard gra- 
nite and gneiss of the Channel Islands and the outer Hebrides, 
and tunnelling its galleries under the spreading base of Coral- 
fina and the numerous Nullipores, both free and surmounted 
by the tangles, or as M. de Quatrefagest found at Guettary, 
in the case of Sabella saxicava, which preferred to bore the 
calcareous rocks rather than the quartz with which they alter- 
nated. It is likewise abundant in the fissures of the shale and 
sandstone, forming tunnels amidst the muddy débris so abun- 
dant in these localities, where Dr. Johnston seems alone to 
have found it. Qérsted, again, gives “sandy tubes” as its 
sole habitation. Vast numbers of the common limpet-shells 
are also invaded by them, their tracks with the loop at the 
bottom being visible from the inner surface as whitish streaks; 
and the irritation frequently causes the mollusk to secrete 
layer upon layer of the nacreous lining. It abounds likewise 
in many other littoral and deep-water shells, such as Buccinum, 
Fusus, Haliotis, Ostrea, and Anomia, and, indeed, in favour- 
able sites, almost upon every shell thick enough to bore into. 
Its presence amidst the shale and sandstone is easily reecog- 
nized by numerous small tubes, composed of agglutinated 
sand and mud (Pl. XTX. fig.1), which project from the surface 
of the stone in dense groups, so as to form in many cases a 
kind of sward of tubes—a habit apparently characteristic of the 
* Archiv fiir Naturges. 1855, p. 108, Taf. 4. f. 11. 
+ Ann, des Se. Nat. sér. 3. Zool. tome viii. 1847. 
