Dr. W. C. Mcintosh on the Boring of certain Annelids. 289 



the fractured blocks in all directions. The second species 

 of stone-borer ( T. stellata = Pomatostegus stellatusj Morch, 

 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. Osier * 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 NereideSj Arenicola piscatorumn^ and Terehella conchi- 

 lega^ as well as that of the Spatangi burying themselves in 

 sand. His figure of T. condiilega^ however, very much re- 

 sembles T. littoralis. Mr. Templetonf fairly describes the 

 perforations of a species, which is probably L. ciliata^ in the 

 limestone rocks of Whitehead, Belfast Lough, and figures the 

 perforated stone and the animal in various positions. Mr. 

 Gamer \ 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 Dijplotis 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 structural distinctio% made at the fifth segment 

 of the body. In the same Transactions, Mr. E,. Templeton § 

 mentions a borer in the corals of the Isle of France called 

 Anisomelus luteuSj 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. QErsted || next describes the boring of Dodecaceria 

 concharum in shells. M. de Quatrefages If 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 moUusca, and 

 thus render its pristine site ambiguous, there could be no 

 doubt about the ancient condition of stones bored by this 8a- 

 hella. In his recent work he refers more than once to the 

 subject**. Dr. Williamsft observed the boring habit of Leu- 



* Phil. Trans. 1826, p. 842. 

 t Loudon's Mag. Nat. Hist. ix. 1836, p. 234. 

 X Zool. Trans, vol. ii. p. 95. 

 § Zool. Trans, vol. ii. p. 27, tab. v. figs. 9-14. 

 II Anniilat. Danic. Consp. p. 44, 1843. 

 i[ Ann. des Soc. Nat. s^r. 3, Zool. torn. viii. 1847. 

 ** Hist. Nat. des Anneles, vol. i. pp. 129 and 133 ; vol. ii. pp. 295, 415, 

 437, 552, 583, 597. tt Keport Brit. Assoc. 1851, p. 208. 



