148 TEREDINID^l. 



up the creeks of the delta. This piece of ebony was 

 pierced in all directions by a species of Teredo having a 

 calcareous sheath. The kind of wood mentioned by 

 Dr. Kirk resembles the ebony of commerce, but is 

 utterly worthless, except as fire-wood ; and therefore it is 

 not at all likely that the piece in question could have 

 been accidentally brought inland, after being perforated 

 in the sea by the Teredo. It sinks in water, is rather 

 brittle, much harder and far more compact than either 

 mahogany or teak, and is full of some mineral matter 

 that quickly deadens the edge of any tool. It does not 

 grow on the coast, nor within 50 miles of it on the 

 Zambesi. Dr. Kirk adds that in the bottom planks of 

 the pinnace belonging to the expedition the shipworm 

 was also found, with its soft parts attached to the finely 

 sculptured valves. The boat was so riddled that the 

 quartermaster pushed a paint-brush through her double 

 planks. This was at Tete, 250 miles from the sea, after 

 the pinnace had remained there six months at anchor. 

 I regret not having space to give in extenso Dr. Kirk's 

 interesting account of all the circumstances connected 

 with this discovery. Unfortunately the specimens were 

 lost on the way home ; but not the slightest doubt can 

 be entertained that the Teredo observed by him inhabits 

 water which is at all times perfectly fresh and sweet. 

 The habits of the Teredo are littoral. When they are 

 met with far from land, the piece of wood which contains 

 them has been accidentally detached and carried out to sea 

 by some marine current. Dr. Lukis noticed that, at Sark, 

 T. Norvegica and T. pedicellata pass more than half 

 their time out of water, during the recess of each tide, 

 when the shipping-stages in which they live are left 

 high and dry. Sir Everard Home confirmed the obser- 

 vation of Sellius, by saying that " the worm appears 



