94 THE ELEMENTS 



lar genus ; but none of those are by 

 any means satisfactory. Mr. Mon- 

 tagu in his Testacea JBritannica has 

 divided this genus into two, under 

 the names Serpula, which are shells 

 attached to other bodies ; and VeV" 

 maculum, shells unattached. But in 

 this division the generic characters are 

 no more definite than that of Linne. 



In Turton^s Linne 48 species of 

 Serpula are described ; and 27 species 

 are ascertained to be inhabitants of 

 the British seas. 



Genus 35th.— TEREDO. Animal 

 a Terebella, with two calcareous, 

 hemispherical valves cut off before, 

 and two lanceotate ones : shell taper- 

 ing, flexous,and capable of penetrating 

 wood. Linn, Syst. 334. Plate 9th, 

 ^g, 35. 



Habitation. The shells of this 

 genus inhabit the bottoms of ships ; 

 and oak poles, which are under water 

 in harbours, &c. One species has 



