188 TRIFORIS. 



T. NiGROCiNCTUs, C. B. Ad. PI. 39, fig. 52. 



Dark chocolate color; whorls about 13-15, with three series of 

 subequal granules, suture excavated, bearing a thread, body whorl 

 with four series of tubercles, and two or three basal ridges below 

 them. Length, 10 mill. 



New England to West Indies. 



Generally considered by European conchologists a variety of T. 

 perveraus, Linn., and perhaps should be relegated to that species. 

 Dark specimens are iinicolored, but lighter ones show the sutural 

 thread darkei- — whence the name. T. modestum, Ads., appears to 

 be the same, and Morch refers here Cerithium pusillum, Pfr. 



T. turris-Thom^, Chenm. PI. 39, fig. 53. 



Whorls 11, each Avith a spiral series of large white tubercles, and 

 a much smaller chestnut colored series, forming a band. 



Length, 5 mill. 



West Indies. 



T. mirabilis, Ads., is a synonym. 



T. iNTERMEDius, C. B. Adams. PL 39, fig. 54. 



Whorls about 12, at first with two, afterwards Avith three spiral 

 series of tubercles, and three additional less nodulous ridges at the 

 base of the body whorl ; reddish brown, with a white spiral band on 

 the lower part of the whorls. Length, 6-8 mill. 



West Indies. 



This is T. turris-Thomce, d'Orb., not Chem. 



T. ORNATUs, Desh. PI. 39, fig. 46. 



Triseriately tuberculate, dark brown, with here and there a white 

 tubercle, and the lower series white banded. Length, 7-10 mill. 



West Indies. 



This and the two preceding species, though nearly related, appear 

 to be distinct ; the present is the most robust of the three. 



Section Sychar, Hinds, 1844. 



T. viTREA, Hinds. PI. 39, fig. 55. 



Pellucid, yellowish white; whorls 15, smooth, rounded, with a 



strong median raised line and a smaller one below it. 



Length, 10 mill. 



Straits of Malacca. 



