286 Dr. W. ©. M‘Intosh on the Boring of certain Annelids. 
out the water with which the bottom of the tube may be filled ;” 
and thus the Annelid “amid the raging billows is securely 
anchored to its cell.” From the siphonal nature of the tube, 
this description cannot apply in any degree. 
Another very common borer in shells, nullipore, and calca- 
reous rock is Dodecaceria concharum, CErst., a Cirratulean 
which has a larger tube, shaped something like a keyhole 
in transverse section, and terminating in a slightly dilated, 
smooth, cecal extremity. This animal likewise lives in the 
fissures of the rocks in the Channel Islands, forming in the 
mud long galleries bent in various ways, but always readily 
distinguishable from those of Leuwcodore. In addition to the 
foregoing localities, a specimen was sent me alive from St. 
Andrews rocks in its characteristic tube in sandstone. In 
this instance the perforation in the stone was lined by a con- 
siderable coating of carbonate of lime, so that it had a smooth 
whitish aspect—as if the animal had not relished constant con- 
tact with the rough grains of sand, and had fashioned a coat- 
ing analogous to the well-known secretion of Teredo. Even 
in the spreading base of Corallina officinalis, the gallery in- 
habited by this animal is often so smooth, and its appearance 
on fracture so characteristic, that the observer is led to suspect 
the existence of some secretion which covers over the rough- 
nesses of the tube and the rocky surface. ‘The bristles (Pl. XX. 
fig. 4) in this species have a dilated and flattened tip with a 
finely serrated edge, and taper to a fine point. The shape of 
- the hooks (figs. 2 & 3) is peculiar and characteristic, and en- 
ables the observer to distinguish the dried remnants at once. 
The animal tinges the spirit of a rich dark-green hue, just as 
Sark specimens of its ally Cirratulus cirratus do, but gives 
no acid reaction to test-paper. The Nereis sextentaculata of 
Delle Chiaje*, which lives in holes in the rocks of the Nea- 
politan shores, is, in all probability, referable to the same spe- 
cies: and the Narganseta corallit of LeidyT is likewise either 
the same or a very closely allied form. ‘The latter bores dead 
portions of Astrangea astreformis. 
A third British borer is Sabella saxicava, Quatref., which, 
according to Messrs. Stewart and Lankester, is found in the 
limestones near Plymouth; and I have found it abundantly 
in Oyster, Pecten, Anomia, and other dead and living shells 
dredged off the Channel Islands, as well as perforating the 
Balani that cover the sides of the Gouliot caves at Sark, near 
* Memorie sulla Storia e Notomia degli Animali senza Vertebre del 
Regno di Napoli, vol. iii. p. 176, tab. 43. fig. 16. 
+ “Marine Invert. of Rhode Island and New Jersey,” Journ. Acad. Nat. 
Se. Philad. ser. 2.-vol. iii. 
