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



codore ciliata^ but did not enter into the modus operandi. M. 

 Marcel de Serres * describes the genus Stoa^ one of the chief 

 characteristics of which is that it perforates West-Indian shells 

 — a fact, however, which had previously been observed by other 

 naturahsts. M. Valenciennes f? in his remarks on the per- 

 forating Echiniy instances the case of a Sijmnculus that bores 

 wood. M. Lacaze-Duthiers % describes, in a careful paper, 

 Bonellia viridisj a Gephyrean which bores calcareous rocks on 

 the shores of Corsica. Prof. Grube § has lately described two 

 other forms beside that first mentioned, viz. Sabella so^icola 

 and Phascolosoma verrucosum^ which perforate the limestones 

 of Martinsica and the island of Lussin in the Adriatic. 



The chemical theory in regard to such borings, it is well 

 known, has frequently been brought forward by zoologists in 

 the instances of Mollusca and Sponges, and lately has even 

 been assumed with regard to the Bryozoa||. Moreover it 

 has more than once been promulgated to explain the means 

 whereby Annelids perforate shells and rocks. Besides those 

 already alluded to, Mr. Osier, for instance, brings forward the 

 case of the Annelids to show that a shell is not essential to 

 the boring-process, and in support of the solvent theory ; yet 

 he could not find any such agent in the animals. Like his 

 successor Mr. Lankester, he gets over the " argillaceous " dif- 

 ficulty by averring that they do not bore in this material, but, 

 more fertile in resources, he hints that they probably inhabit 

 cavities bored by other animals If. A. S. (Ersted considered 

 that Dodecaceria concharum bored partly by aid of the secre- 

 tion of its alimentary canal (which, says he, contains muriatic 

 acid), and partly by aid of its hooks. Sir J. Dalyell** likewise 

 thought that the tube of this animal might be enlarged by 

 some solvent. Mr. Spence Bate ft accounts for the majority 

 of marine borings by an ingenious theory which adjroitly 

 shifts the onus of the solvent from the animal itself to its sur- 

 roundings ; or, in other words, he avers that the solution of the 

 difficulty and the rock is achieved by the agency of free car- 

 home acid held in solution hy sea-water. He instances " the 

 groove sunk by the SpiroglyphuSy which Annelide afibrds a good 

 example to illustrate the theory ; for it not only sinks a groove 

 in the shell on which it has erected its own, but, should its 

 contortions bring it into contact with any portion of its own 



* Ann. des Sc. Nat. ser. 4. torn. iv. 1855, p. 230, pi. 8 c. figs. 1-8. 

 t Compt. Rend. Acad. Sc. Paiis, torn. Ixi. 1855. 

 X Ann. des Sc. Nat. ser. 4, Zool. torn. x. p. 49, pis. 1-4. 

 § Ein Ausflug nach Triest und dem Quarnero, pp. 47, 48, 1861 ; and 

 Die Insel Lussin u. ihre Meeresfauna, 1864. 

 II Ann. Nat. Hist. ser. 3. vol. xvii. p. 472. 



U Phil. Trans. 1826. ** Pow. Great, vol. ii. p. 210. 



tt Transact. Brit. Assoc. 1840, p. 73-75. 



