180 MOLLUSCA. 
base a series of larger bead-like papille, and above these three series 
of smaller beads; the space between the lowest of these and the basal 
series being widest, and somewhat excavated; all the intermediate 
spaces are marked by numerous, very minute, revolving, raised lines, 
which, on inspection with a magnifier, are also found to be minutely 
barred with the lines of growth; periphery of the last whorl acutely 
angular: colour, before cleaning, a very dusky green ; when touched 
by acid, bright emerald-green: base pale, cinereous, marked with 
dusky, raised, revolving, thread-like lines, which are largest near the 
umbilical pit, and have the interspaces finely indented; aperture 
rhomboidal, the outer lip very oblique, without internal strie; colu- 
mella contorted at base, forming an obtuse tooth ; smooth and rounded 
elsewhere. 
Diameter four-fifths of an inch; axis five-eighths of an inch. 
Inhabits New Zealand. 
There are several species which have the same kind of umbilical 
vortex, the same general form, and the same general sculpture. The 
peculiarity of this species is the arrangement of the granules above the 
fine secondary sculpture in which they are placed, the excavated base, 
with its thread-like, unbeaded lines, and the two white ribs in the 
umbilical pit. It may be compared with T. vernus, Chem. 
Figure 217, profile of the shell; 217 a, base of the shell; 217 0, and 
217 c, details of the sculpture of the side and base, enlarged. 
TROCHUS PRUNINUS (Gould). 
Testa solidula, elevata, ovato-conica, levis, nitida, prunina, linets capil- 
laceis albis numerosis cincta: sptra anfractibus septem convexiusculis, 
ultimo subangulato ; sutura profunda: apertura subcircularis ; colu- 
mella rotundata, alba, anticé roseo-tincta, subsinuosd: interior mar- 
garitacea, vivide wridescens. 
Trochus pruninus, GouLp ; Proceed. Boston Soc. Nat. Hist., 111. 90. 
March 1849. Expedition Shells, 55. 
