74 THE NAUTILUS. 
bly been adopted for greater safety in the exposed tree tops; to the 
same end every superfluous atom of weight has been abandoned, 
the shell reduced to the thinnest, and the reflected lip dispensed 
with. Under the lens the apex is seen to be of one and a half 
whorls, black or darker than the adult shell, smooth and subglobose, 
Oblique growth lines are the predominant features of the adult 
sculpture; by flashing the shell in the sunshine under a lens, an 
extremely minutely shagreen surface is perceptible in the gleam, and 
here and there broken lengths are decipherable of engraved spiral 
lines. Viewing the shells of these three species by transmitted light 
the color markings are seen as translucent spaces in the opaque 
shell. I should interpret these signs as indicating a descent from 
an ancestor like naso and macgillivrayi through a form very close to 
bidwilli Pfeiffer. 
The minute almost imperceptible shagreen surface may represent 
the coarse sculpture of naso; the evanescent spiral lines are tracea- 
ble from the clear cut lines of macgillvrayi through the fainter 
sculpture of bidwilli Pfr., to their vanishing representative in bid- 
willi Cox. But the minute subglobose apex and especially the 
translucent spiral color bands ally this group unmistakably with 
Papuina. Admitting this, in default of anatomical examination, it 
will be necessary to rename the shell hitherto known as Bulimus 
bidwilli Cox, lest it should clash with that other Papuina described 
by Pfeiffer as Helix bidwilli. I therefore propose that in allusion to 
its peculiar habits, it be henceforth called Papuina folicola. 
Between these leaf-dwelling Papuina of Queensland and Bulimus 
mageni Gassies, of New Caledonia, I note a strong resemblance in 
color, form and sculpture, but especially in their translucent color 
bands. Until further research settles authoritively the position of 
this species I would provisionally class it with the foregoing. 
SAN PEDRO AS A COLLECTING GROUND. 
San Pedro, California, is remarkable for the number and variety 
of recent and fossil mollusks. 
New forms and an unusual abundance of known species are con- 
stantly being found. 
This is due in a great measure to the extension of the Government 
breakwater, which has made changes in the sea currents near the 
