Dr. W. C. M‘Intosh on the Boring of certain Annelids. 287 
low-water mark, my attention having been first directed to the 
latter site by Dr. Bowerbank, who kindly sent me dried spe- 
cimens. In these caves the tube of the Annelid is often coiled 
in its groove beneath the Balanz, and then pierces the shell of 
the latter to appear on the upper surface. It likewise bores 
abundantly in Cellepora pumicosa, and in one instance had 
bored quite through the valve of a living Pecten pusio. It 
often occurs in the same oyster-shell in a combined attack 
with Gastrochena dubia, Leucodore, and boring sponges, or 
sometimes places its tubes in groups in convenient fissures of 
the shell without boring, so that they can be dislodged en 
masse like short and contorted tubes of Tubularia indivisa. 
Another site is under empty limpet-shells amongst muddy 
débris, part of each tube being inserted into a perforation in 
the shell; while, again, the cracks and fissures of the rocks 
near low-water mark afford a very favourite habitat im the 
Channel Islands, and their tubes are often seen projecting 
through incrusting sponges and Ascidians, both simple and 
compound. The species has a tough horny tube, whose ex- 
posed portion is furnished with minute grains of sand; but the 
immersed portion is hyaline and more delicate. ‘The boring 
in the shell and limestone is circular, and, though often more 
or less curved or coiled, it is not to be confounded with the 
work of Dodecaceria or Leucodore. Ineed not allude further 
at present to the structure of the species, save to observe that 
its branchiz are speckled with pale green and white, and fur- 
nished with two or three brown pigment-specks exteriorly, 
and that its hooks (Pl. XX. figs. 5 & 6) (which are accompanied 
by broadly spear-tipped minute bristles, fig. 7) and bristles 
(fig. 8) have the structure represented. The body shows a 
distinct acid reaction towards the posterior end, and especially 
at the tip of the tail. 
The fourth native borer is a little Sipunculus, which exter- 
nally appears to be identical with S. Johnston of Forbes. It 
occurs in limestone on the shores of the Isle of Wight, bores 
into the spreading base of Corallina with the foregoing forms 
in the Channel Islands, tunnels the mud in the fissures of 
various rocks, and one occurred in a shell sent by Mr. Gwyn 
Jeffreys in his rich Zetlandic collection of 1867. The form of 
the perforation in the latter case is club-shaped ; and a young 
specimen had bored its tiny gallery from the tube of its parent 
—a very rare occurrence amongst the true Annelids. In this 
instance the tubes of Campanularia verticillata had taken 
possession of several of these minute galleries after the death 
or exit of the original inhabitant. This boring Sipunculus is 
quite neutral to test-paper. 
20* 
