Dr. G. C. "VVallicli on the Boring Powers of minute Annelids. 57 



its long axis towards the axis of the septal orifices of the Bilo- 

 CM/ina-segments, is of sufficient size to be visible by the naked 

 eye, and presents but one perfect revolution, as shown in fig. 3 

 of the last woodcut, there being no trace of a fractured margin 

 of attachment at any portion of its surface. 



Before concluding, I would also mention having met with 

 several examples of Foraminiferous shells, brought up from the 

 greatest depths, perforated, in all probability, by the minute 

 boring Annelids that construct and inhabit the tubes of which I 

 have made mention in my " Notes." The extreme delicacy of 

 the inhabitants of these tubes has, as yet, completely baffled 

 me in all my attempts to extract them and determine their 

 character. In addition, however, to the tubes, formed in so 

 singular a manner, of innumerable carefully selected Globi- 

 geriaa-shells cemented together, there also occur other tubes, 

 in which the internal layer is a cylinder of tough membranous 

 material with a rich sienna tint, whilst its outer surface is 

 strengthened and protected partly by numerous Globigerina- 

 shells, as in the previous case, and partly by a layer of sihcious 

 spicules, probably derived from some minute sponge. The per- 

 forations in the shells are invariably of one character, and consist 

 of an aperture bored through and through, but having the entire, 

 thickness of the shell-wall, from the inner surface to the outer 

 one, as it were countersunk. Accordingly, in section, such a 

 perforation presents a truncated cone, the apex of which is di- 

 rected inwards. 



It has repeatedly been observed that, in the manufacture of 

 telegraphic cables, it is a matter of vital importance to guard 

 against the attacks of Annelids capable of thus penetrating hard 

 substances at the greatest depths. Owing to the difficulty of 

 boring into gutta percha, unless under the action of chemical 

 solvents, I cannot conceive much danger is to be apprehended 

 from its employment as the coating medium. If Annelids 

 are able to drive their boring apparatus through gutta percha, 

 it can only be when it has assumed the brittle, macaroni-like 

 structure peculiar to it after long-continued exposure to heat, or 

 in the case of impure and adulterated gutta percha. Pure 

 caoutchouc, I do not hesitate to say, is impervious to a boring 

 apparatus like that of the Teredines, — unless, as before men- 

 tioned, under the action of a chemical solvent, when, of course, 

 no boring tool is necessary to render the mischief complete and 

 fatal. And, lastly, there is this consolation for the advocates 

 of gutta percha and caoutchouc coverings for submarine cables : 

 — If their little hidden enemies at the bottom of the sea are so 

 far advanced in civilization as to be able to discriminate when 

 they ought to use their augers, or fall back uj)on their chemical 



