Anatomy of Centfiium Telescopium. 433 



Through the mantle are readily traced the rectum, matrix, sac of vis- 

 cosity, stomach and liver. On opening this along the left side, the 

 branchiae, rectum and matrix are seen in situ. 



The organ of respiration consists of a long single row of triangular 

 plates, which are less and less elevated as they are more distant from the 

 margin, and are at last little more than parallel w^rinkles. The vessel 

 which carries the arterial blood to the heart is distinctly traceable on the 

 left side, running down to the heart which as usual lies close to the sac of 

 viscosity ; the auricle is small and curved ; the ventricle much firmer 

 and obovate. This gives off two large vessels and a smaller one, of 

 which one supplies the liver, but before it reaches it gives off a large 

 vessel above the rectum : the various ramifications in the liver are well 

 marked ; some of them are represented in fig. 3. The second vessel 

 given off from the ventricle runs parallel with the heart and pulmonary 

 artery to supply the anterior parts of the animal. The third passes 

 immediately above a particular organ [m. fig. 5.) to be mentioned pre- 

 sently. We were not able to trace returning vessels. 



The parts of the mouth are very small ; the tongue very short, fur- 

 nished as usual with regularly disposed reflexed teeth ; the salivary ducts 

 enter on each side above the point of insertion of the tongue, and after 

 running down on either side of the cesophagus, suddenly turn back ; and 

 there the glands are seen curling from side to side, and at length united 

 together just below the apex of the tongue. A single short flat ligament 

 is attached to the mass of the mouth behind, and inserted into the foot 

 beneath the oesophagus. 



The cesophagus is very long, runs backwards to the stomach in the 

 direction of the volution, and enters into it laterally at the further end. 

 The stomach is of a veiy curious and complicated srructure. It is 

 divided by valvular processes into three portions, which are not however 

 distinctly marked externally. 



The first of these occupies rather more than the upper half of the 

 whole stomach. It is into this, immediately above the constriction, that 

 the oesophagus enters obliquely between two plates. Of these the 

 external one runs down to the apex of the stomach ; the inner runs only 



Vol, V. FF 



