GASTEROPODA. 383 
Figures 489, 489a, 4890, outer, inner, and lateral views of the 
shell. 
CapULUS SAGITTIFER (Gould). 
Testa parva, tenuis, lucida, candida, semiglobosa, apice mediano, dex- 
trorsum inchinato, acuto: extus lineis lacters radiantibus, papillas sagit- 
tatas gerentibus insculpta: apertura sub-circularts ; cavositas pro- 
Sunda ; cicatricibus bené tmpressts et septo filiformi junctis. 
SHELL small, thin, pure white, translucent, nearly semiglobose, the 
apex median, acute, slightly inclined to the right, not approaching the 
margin of the aperture; surface beautifully sculptured with fine, 
radiating lines, on which are series of arrow-headed beads, arranged 
in quincunx, and of a more opaque-white colour, giving the surface, 
under the microscope, a delicate, squamose appearance. Aperture 
nearly circular, lip simple; cavity of the beak profound, having a 
thread-like diaphragm between it and the margin, connecting the 
muscular impressions, which are distinctly marked. 
Diameter one-fourth of an inch ; height one-tenth of an inch. 
Habitat uncertain. 
This species is well distinguished by its peculiar and beautiful 
sculpture, the radiating lines seeming to be made up of chains of arrow- 
heads. 
Figures 486, 486 a, 486 0, three views of the shell, enlarged; 486 c, 
details of sculpture, magnified ; 486 d, natural size. 
