176 SPECIFIC 



out. These processes vary in different specimens 

 both in number and in length. The aperture is 

 distinctly of the same shape as that of a Turbo, and 

 hence the opinion may have arisen that the whole 

 is parasitically formed by a coral insect which takes 

 a certain species of Turbo for its nucleus. In op- 

 position to this it may be stated, that there is no 

 outward appearance of spire beyond the first whorl; 

 that the aperture bears every mark of the recent 

 passage of an inhabitant, being smooth, and free 

 from all obstruction. That there is indeed no fo- 

 reign shell is plain, from the circumstance of the 

 substance being of the same nature in every part, 

 and the inside of the outer lip showing the founda- 

 tion of the spots through a thin slimv covering. 



What then is it to be denominated ? This will 

 hardly be answered quite satisfactorily till the in- 

 habitant be known, and till it be observed whether 

 he have any organs with which to build this coral- 

 like edifice. That it is however entirely the work 

 of a molluscous worm, upon the whole appears 

 most consonant with reason. If this be the case, 

 it must, in the Linna-an system, be a Tiubo, and 

 it is proposed to call it specifically madreporoides. 



