Dr. W. C. M‘Intosh on the Boring of certain Annelids. 289 
the fractured blocks in all directions. The second species 
of stone-borer (7. stellata = Pomatostegus stellatus, Mérch, 
Schmarda, &c.) described by Dr. Abildgaard has an operculum 
composed of three flats or plates raised one above another, and 
supported by a central column or axis, and likewise has been 
found perforating coral reefs. Mr. Osler * alludes to the 
abundance of worm-perforations (when treating on the same 
subject) in the Mollusca, thus—‘‘ The boring Annelids are in- 
numerable in calcareous rocks, and are found to attack every 
marine shell almost as soon as it has acquired sufficient thick- 
ness to afford them a nidus ;” and he further instances the cases 
of the Nereides, Arenicola piscatorum, and Terebella conchi- 
lega, as well as that of the Spatangi burying themselves in 
sand. His figure of 7. conchilega, however, very much re- 
sembles 7. littoral’s. Mr. Templeton + fairly describes the 
perforations of a species, which is probably L. edliata, in the 
limestone rocks of Whitehead, Belfast Lough, and figures the 
perforated stone and the animal in various positions. Mr. 
Garner { refers to the subject in the Zoological Transactions, 
thus, “‘ Certain Annelides apparently possess the power of ex- 
cavating. The rocks on our coast are pierced by a minute worm, 
probably of the genus Diplotis of Montagu ; it is strongly cili- 
ated, but its mouth does not appear adapted for making its way 
into such hard substances.”’ His figure is doubtless intended 
to represent Leucodore; but only two eyes are shown, and 
there is no structurai distinction made at the fifth segment 
of the body. In the same Transactions, Mr. R. Templeton § 
mentions a borer in the corals of the Isle of France called 
Anisomelus luteus, which has numerous long, hollow, prehen- 
sile tentacles, that seize prey like Sapajous’ tails. It forms 
for itself a minute tube on the surface, as well as bores into the 
coral. M. Cérsted || next describes the boring of Dodecaceria 
concharum in shells. M. de Quatrefages {| details the perfora- 
tions of Sabella saxicava, and points out the interest which 
such would have to the geologist ; for though a Helix might 
perforate limestone like the marine lithophagous mollusca, and 
thus render its pristine site ambiguous, there could be no 
doubt about the ancient condition of stones bored by this Sa- 
bella. In his recent work he refers more than once to the 
subject**. Dr. Williamstt observed the boring habit of Leu- 
* Phil. Trans. 1826, p. 342. 
+ Loudon’s Mag. Nat. Hist. ix. 1836, p. 234. 
{ Zool. Trans. vol. ii. p. 95. 
§ Zool. Trans. vol. ii. p. 27, tab. v. figs, 9-14. 
|| Annulat. Danic. Consp. p. 44, 1843. 
4] Ann. des Soc. Nat. sér. 3, Zool. tom. viii. 1847. 
** Hist. Nat. des Annelés, vol. i. pp. 129 and 133; vol. ii. pp. 295, 415, 
457, 552, 583, 597. t+ Report Brit. Assoc. 1851, p. 208. 
