182 TRIFORIS. 



T. ANGUSTISSIMUS, Desh. PI. 38, fig. 8. 



Shining, whitish, marbled with chestnut; whorls 14, narrow, with 

 two series of rounded tubercles, last whorl with a peripheral carina 

 and several raised lines on the base. Length, 4 mill. 



Isle of Bourbon. 

 T. PFEIFFERI, Crosse. PL 38, fig. 9. 



Rather thin, subtranslucent, whitish, regularly maculated with 

 chestnut, whorfs 18, with three spiral rows of beads, the middle one 

 minute, the lower largest, and bordered below by a thread which 

 is articulated with white and chestnut, base smooth. 



Length, 8 mill. 



Gulf of St. Vincent, N. Australia. 



T. MIRIFICUS, Desh. PI, 38, fig. 10. 



Yellowish white, whorls 15, narrow, each with two rows of pel- 

 lucid granules, and a wide concave interspace, on the body whorl 

 four rows of granules, which are smaller. Length, 7 mill. 



Isle of Bourbon. 

 T. DECORATUS, C. B. Adams. PI. 37, fig. 4. 



White, maculated with somewhat quadrangular large chestnut or 

 chocolate spots, with three nearly equal spiral rows of beads and 

 intermediate, narrow, deep channels, body whorl anteriorly with 

 two additional smaller, more or less beaded spiral ridges ; whorls 

 16, planulate, the suture deeply grooved. Length, 14 mill. 



West Indies, Florida. 

 Section MASTONIA, Hinds, 1844. 

 T. VIOLACEUS, Quoy. PI. 38, figs. 11, 12. 



With convex sides and base, violaceus, w r horls 20, suture slightly 

 grooved, whorls with two rows of tubercles, which are rounded, rosy 

 white. Length, 8-10 mill. 



New Caledonia, New Ireland, Viti Is. 



T. Ducosensis, Jouss. (fig. 12), was separated because it has only 

 one canal-opening, whilst the true violaceus has a dorsal one remain- 

 ing ; a merely individual difference, as I have explained. 



T. RUBER, Hinds. PI. '38, figs. 13-16. 



Pink, with the two rows of granules on each whorl, which are 

 often yellowish, suture marked by a raised line. Length, 9 mill. 



New Ireland, Tahiti, Isle of Bourbon. 



T. roseus, Hinds (fig, 14), appears to differ only in the interposi- 

 tion of a minute additional series of tubercles ; a condition fore- 



