GTJPPY SHELLS OF TRINIDAD. 369 



diate between T. plicata and T. magnified, differing from the 

 former in ornamentation and general shape. On a tablet in 

 the British Musenm the name dissimilis is applied to our 

 species ; but I have not been able to find any authority for 

 that name, which I now adopt for the shell. 



The animal is furnished with two long siphons separate 

 for the whole of their length and coarsely fringed. The 

 epidermis along the posterior margin extends beyond the 

 the shell and covers the bases of the siphons. 



Tuesday, 13/A April, 1868. 



R. J. Leciimere Guppy, F.L.S., F.G.S., &c, President, in 



the Chair. 



The following Donations were announced : 



"Journal of the Society of Arts" Nos. 819, 824, 825, 

 826, 827, 837, 838, 832, 840. Presented by the Co- 

 lonial Government. 



The following communication was read : 



" On the Manufacture of Sugar by Evaporation." By The 

 Hon. Henry Stuart Mitchell, M.D, Ph.D. 



The last communication which I had the pleasure of sub- 

 mitting to tbe Association, was an examination of the me- 

 thods in use or proposed for obtaining the juice of the Sugar 

 Cane in as nearly a state of sugar and water as possible. 

 Experience has decided clearly in favour of slicing the cane 

 and then washing out the saccharine element with water. 

 This may be done in more than one way, but it may be af- 

 firmed that science points out as the most perfect mode that 

 in which the cane after the process of slicing is exposed to 

 such a heat under 212 as will be sufficient to fix the albu- 



