DENTALIUM. 235 



The present species inhabits the coralline zones of the 

 South Devon coasts, five or six miles from land, in twelve or 

 fifteen fathoms water. 



I had written thus far when I received from Paris M. 

 Deshayes' memoir on the Dentalia, which I had not seen for 

 twenty years, and its contents had nearly passed from my 

 memory; on looking it over I find that the differences be- 

 tween that gentleman and myself are more important than 

 I was aware of, but I am not inclined to abandon my own 

 views. I am also "glad to find that I am enabled to fill up 

 many gaps as regards the functions and habitudes of these 

 animals. 



This gentleman, in stating the anus in Dentalium to be 

 posterior, observes that it is the only molluscum that has it 

 so situated; but this anomaly, if it be so, I think I have 

 disposed of. 



Those organs which I consider to be the symmetrical 

 branchiae are termed by M. Deshayes the lobes of the liver, 

 each pouring into the stomach the bile by their biliary vessels. 

 I cannot persuade myself that this view is correct; I have 

 submitted them to the microscope, and in each principal 

 strand I have seen the leading vein distended with red blood, 

 as well as the net-like connecting ramifications; I there- 

 fore consider what are called the biliary vessels to be the 

 branchial veins conveying the blood to the heart instead of 

 bile into the base of the stomach. M. Deshayes in his figure 

 has omitted to mark the vein which runs at the dichotomous 

 points of his organ, which, when viewed under high powers, is 

 very visible, and which I take to be the branchial vein. 



What I term the salivary glands, are the branchiae with M. 

 Deshayes, combining the functions of tentacula : he does not 

 mention such glands. I must consider this assumption in- 

 correct ; and to support this opinion I state that the heart is 

 separated the whole length of the stomach from the bases of 

 what M. Deshayes terms the branchiae : this is a position 

 without parallel, as that organ is invariably in the closest 



