210 PROCEEDINGS OP THE ACADEMY OF 



RiSSOINA MILLECOSTATA, Gam, pi. 2, fig. 3. 



Shell elongate-oblong, sub-cj-lindrical, rather thin, white ; spire 

 long, convex, apex acute, the upper whorls tapering more rapidly 

 than the lower ones ; whorls 11, flatly convex, closely striated with 

 transverse elevated lines, longitudinally ribbed ; ribs small, nume- 

 rous, closely set, slightly o1)lique, gradually becoming obsolete 

 toward the lower part of the whorls ; suture deeply incised ; aper- 

 ture sub-ovate, nearly vertical, about a third the length of the 

 sliell ; peristome thick, slightly sinuous above ; basal sinus rather 

 indistinct ; columella and parietal region with a thin callus. 



Length 9 mill. 



Hah. Viti Isles. (Coll. Garrett.) 



Onl}^ a solitary but perfect example found. Its most obvious 

 character is its numerous ribs, transverse lines, and absence of the 

 external rib to the outer lip. 



RiSSOINA ORYZA, Garr., pi. 3, fig. 4. 



Shell small, oblong-ovate, solid, smooth, shining, Avhite ; spire 

 moderatel}' elevated, rather rapidly tapering, apex obtuse; whorls 

 6-7, flatly convex, the last one rather large, slightly compressed 

 beneath; suture faintly impressed and broadly margined beneath ; 

 aperture rather large, oblique, sub-ovate ; peristome thick, dilated ; 

 columella oblique. 



Length 2 mill. 



Hah. Viti Isles. (Coll. Garrett.) 



Three examples found in beach sand at Kiva Island. It belongs 

 to the same group with B. curta and R. semiplicata. 



RiSSOINA IIORRIDA, GaiT., pi. 2, fig. ,5. 



Shell small, elongate-oblong, thick, vitreous, white ; spire rather 

 long, graduall}^ tapering from the body whorl, apex obtuse ; whorls 

 7, longitudinally ribbed, ribs large, closely set, sliglitlj^ oblique, 

 crossed by equally large spiral ridges, two on the whorls of the 

 spire, and four on the sliort body whorl, their points of intersec- 

 tion acutely papillose ; the deep interstices with elevated trans- 

 verse strife ; suture deeply incised and crenulate ; aperture sub- 

 ovate, about one-fourth the length of the shell ; peristome very 

 thick, somewhat five angled. 



Lengtli 3 mill. 



Hah. Viti Isles. (Coll. Garrett.) 



A ver}' rare species remarkable for its bold sculpturing. 



