Victorian Species of Teredo. 117 



The destruction of these pests has proved a matter of considerable 

 anxiety. Countless schemes having been advanced, adopted, and 

 found wanting. An American plan, as quoted by Marshall in tin- 

 Journal of Conchology, 1914, p. 2<>7, shows sonic practicability, and 

 should have a fair measure of .success. It is as follows: — "The 

 latest method to he adopted for overcoming this destruction and 

 loss to wharves, harbours, and submarine works generally, has been 

 successfully carried out by American contractors who can now 

 electrocute them by millions, and although the process is not 

 altogether permanent in its effects, yet by occasional applications 

 it is proving sufficient to overcome the difficulties experienced in 

 many extensive operations, and to supersede the use of divers and 

 other highly-skilled operatives. The method of electrocution is 

 carried into effect by the use of a floating electric-power plant, 

 capable of generating heavy current* of electricity at a compara- 

 tively low intensity. A net work of wires is first lowered into the 

 sea facing the wharf or harbour to be attacked, and these are 

 coupled with one of the poles of the dynamo on the vessel; similar 

 wires are then suspended beneath the ship in electrical contact with 

 the other pole. Directly the current is switched on, electrolytic 

 action occurs in the sea water between the two metal nets, and 

 chlorine gas is thereby liberated. This deadly gas envelopes the 

 Teredines in their borings, and speedily causes death." 



From the timber mentioned in this paper we have obtained and 

 critically examined over 300 pallets.' Four species, all of which 

 Avere detected in the one piece of timber, at Lakes Entrance, three 

 of them also being present in the timber of the piles at Portsea Pier, 

 constitute the representation of shipworms in Victoria, as far as we 

 have been able to ascertain; three at least most probably having been 

 introduced by ships from European localities. 



They are as follow : — 



Teredo navalts, Linn. 

 1767. Teredo navalis, Linn. Syst. Nat. ed. 12, p. 1267. 

 1806. Teredo navalis, Linn. Home, Phil. Trans., pi. 12. 



f. 7-10. 

 1828. Teredo navalis, Linn. Chiaje, Memorie. , Vol. IV., 



pp. 23 and 32, pi. 54, f. 2 and 8. 

 1853. Teredo navalis, Linn. Forbes and Hanley, Brit. 



Moll., Vol. I., p. 74, pi. 1, f. 7. 8, and pi. 18, f. 



3. 4. 

 1862. Teredo navalis, Linn. Chenu, Man. de Conch., Vol. 



II.. p. 10, f. 59. 



