188 NATURAL HISTORY. 



giganteaj of.the habits and history of which very little seems as yefc 

 to be known to concholo£ists. 



I am led to this conclusion by the discovery of such specimens as 



those in the group marked No. 6, showing a septum or division 



running longitudinally down the tube for some distance from the small 



or upper end in such a manner as to divide the tube into two. These 



two divisions are in fact the cases of the two siphonal tubes of the 



animal — one respiratory and the other excretory — which were closed 



at will by means of two triangular pallets working loosely within the 



shell. The union of these two tubes into one through the greater part 



of their length is the characteristic feature of the Pholadidse. To the 



family of Pholadida3 the Teredines are now determined to belong. 



But it was long before the Kuphus, which I believe these specimens 



to be, was admitted to a place among the Teredines. M. Rang, 



who under the name of Septaria excluded Teredo gigantea (Kuphus) 



from the genus Teredo, while observing that it very closely 



approximates the Teredines and the Fistulana?, thus describes it : — 



u Animal unknown; shell unknown; tube calcareous, thick, solid, 



in the shape of a very elongated cone, and irregularly flexuous, 



furnished internally with small incomplete annuliform septa, 



terminated at one of its extremities by a convexity, and at the other 



by two slender and separated tubes." 



Eumphius figures, under the name of Teredo arenaria^ a species of 

 tubular shell found in shallow water, among mangrove trees 7 

 apparently identical with that described by M. Rang, and 

 represents the double tube at the smaller end as branching into 

 a distinct bifurcation. This of course is a material difference from the 

 specimens now before you. 



Lamarck, still excluding this species of Septaria, which he calls 

 Arenaria, from the Teredines, recognised only two species of Teredo, 

 viz., Navalis and Palmulatus, The latter he thought differed only in 

 its greater size from the former, which is the species long and 

 unfavourably known to sailors as the borer through the bottoms of 

 wooden ships. 



In 1797 Mr. Griffiths discovered at Sumatra a tubular shell 

 apparently of a species nearly identical with these before you. He 

 noticed the difference in the structure of the double tube at the 

 smaller end between his specimens and those figured by Rumphius, 

 but ascribed it to the difference of situation in which they were found. 

 Mr. Griffiths' specimens were procured from a small sheltered bay, with 



