186 



explanation. The materials only enable us thus briefly to 

 notice it here. 



109. T. SANDWIZENSIS, ? 



Of this I can obtain no information, except that it occurs 

 in a French catalogue. 



EXCLUDEND.E. 



T. vittata, Lamarck, Encyclop. pi. 402, f. 4, a. b. 

 T. granulosa, Lamarck, Hist, des Animaux. v. vii. 

 p. 291. 



T. lineolata, Sowerby, 1. c. p. 76. 

 T. tahitensis, Gray, 1. c. p. 63. 

 T. polita, Gray, 1. c. p. 63. 



The synonomy of these, together with a list of the fossil 

 species, will be found in my Synopsis of the Genus contained 

 in the Proceedings of the Zoological Society for 1843, 

 p. 166—168. 



