26 PHILINE. 
Section Laona A. Adams. 
Laona Av., Anu. Mag. N. H. (3), xv, p. 324 (April, 1865). 
P. zonata A. Adams. Unfigured. 
Shell dull white, ornamented with two wide transverse red-brown 
bands ; latticed with close, delicate, crenulated longitudinal lamel- 
lee and concentric strive. (Ad.). 
Osima and Yobuko, Japan (Ad.). 
Laona zonata A. Ap., Ann. Mag. N. H. (8), xv, p. 324, (April, 
1865). 
This species is type of the group Laona, reckoned to be of generic 
rank by Adams, and thus defined :— 
“Shell semiovate, thin, rimate, roughened by lamellose growth 
striz ; spire concealed ; last whorl large and rounded ; aperture 
ainple, oblique; roundly-oval ; lip receding, arcuate ; inner lip sim- 
ple. The British Bulla pruinosa belongs to the same group, which 
offers the peculiarity of a decussate surface. The form of the shell 
is also so different from that of any other division of Bullide that I 
consider it desirable to point out the significance of these shells by 
giving them a distinctive name. The animal is unknown.” 
P. pruinosa Clark. PI. 4, figs. 73, 74, 75, 76, 77, 78. 
Shell oval, tumid, but compressed or pinched in below the apex, 
more solid than any of its congeners, nearly opaque, glossy in the 
young only; sculpture, numerous strong and irregular longitudinal 
wrinkly strize (fringed at their edges) and finer spiral strive, which 
by intercrossing give the surface a reticulated and frosty aspect, or 
that af lace work ; the reticulation is less distinct in full grown spe- 
cimens; the very young have spiral rows of circular dots as in P. 
punctata ; edges of the mouth plain; color white, with frequently 
a broad tawny band round the middle and a tinge of the same hue 
on the upper part; these markings are rather evanescent, and ap- 
pear to be superficial; spire very small, sunk below the apex or 
crown, which is considerably thickened; whorls 24. irregularly 
twisted and indistinct; suture deep and excavated; mouth oval, 
contracted above by the periphery and inflexion of the outer lip; 
curved below; it occupies about two-thirds of the under surface; 
outer lip flexuous, widely indented in the middle, and bending in- 
wards above ; edge often thick ; the top slightly exceeds the crown 
